work and energy diagram Creately diagrams can be exported and added to Word, PPT (powerpoint), Excel, Visio or any other document. Energy is detected only because of its effects. To figure out the total work done on, or by, a gas system, they use the formula W = P (delta)V. The internal energy of a system changes in magnitude as heat is added to or removed from the system or as work is done on it or The work-energy theorem states that the work done by the net force on an object of mass m equals the change in kinetic energy of the object. Step 2 – Find the change in internal energy for this process. v2 = u2 – 2as. In this article, we will learn all about the concept of work, power and energy. E. Power = W/ t = E/ t. 4. (1) The total energy consumption value is divided by 4. b. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Total Energy Consumption = Body weight (Kg) × 4 KJ × 24 hours/day / 4. in order to transfer energy to an object you've got to exert a force on that object the amount of energy transferred by a force is called the work done by that force the formula to find the work done by a particular force on an object is W equals FD cosine theta W refers to the work done by the force F in other words W is telling you the amount of energy that the force F is giving to the In physics, the potential energy of an object depends on its position. 9. 4. The work done by a gas not only depends on the initial and final states of the gas but also on the process used to change the state. In the diagram below, determine the speed of the block at each point. If the system does work, the energy comes from heat flowing into the system from the reservoir; if work is done on the system, heat flows out of the system to the reservoir. Apply calculations to these energy changes and transfers. 4 Work 9 5. Write These Down on the Wheel. Kinetic energy depends on speed and mass. They investigate the transformations of energy involved in turning the blades of a hydro-turbine into work, and experiment with how weight affects the rotational rate of the waterwheel. Draw and label two short horizontal lines to mark the energies of the reactants and products. 6 eV –40. Energy is power integrated over time. Which letter indicates the potential energy of the reactants? ___a___ 4. Based on your model calculate: the theoretical speed at which the marble reaches the bottom of your roller coaster track assuming no loss of mechanical energy. Work Work is the energy interaction between a system and its surroundings. 66-meter-high refrigerator to the top of a 0. 0 m/s on a horizontal surface. Become part of our mission today, and transform the learning experiences of students everywhere! (1) light energy (2) nuclear energy (3) gravitational potential energy (4) internal energy 17 How much work is done by the force lifting a 0. Net work done results in a change in kinetic energy as per the work-energy theorem. Which cart shown below has the greatest kinetic energy? (1) (3) (2) (4) 3. The Pressure-Enthalpy (P-h) Diagram Hence, work is said to be done when a constant force is applied to an object which causes the object to move in the same direction as the force is applied. = 50 x10 -3 x1000= 50kg. Work equals 60 units of energy transferred. Power. Work done in diagram II = mgh. [2]b Determine the maximum vertical height attained by the skateboarder assuming that 30% of the initial kinetic energy is lost as heat due to friction along the ramp Solar energy production encompasses several power sources, both passive and active. In the diagram below, the spring has a force constant of 5000 N/m, the block has a mass of 6. To +W From -W - Constant force: F x ma x d v v v v axd ax 2 2 2 0 2 2 0 2 Work done by the force = Energy The equation for work is: W = Fapplied x delta d (where 'W' is the work done (J), 'Fapplied' is the force (N) and delta d is the displacement (m). The other nuclear energy process is actually the opposite of fission. Calculate the net work done by the forces on the air cart using W = FL cos (θ) for each trial. 3 meter from a table? (1) 0. K is to mass and K is to v2 (double the mass—K doubles, double the velocity—K quadruples). KJ/mol Reaction coordinate (time) a. 18 kJ. In fact, work is defined as the change in energy. Theory: In Chapter 7 of your textbook, there are a couple of different formulas that may be called “work-energy theorems,” depending on the context. There must be a hump in the curve to represent the energy level of the activated complex. a. Step 1: Coordinate system. It does this by bringing a working substance from a higher state temperature to a lower state temperature. Let the energy in the flywheel at A = E, then from Fig. I have normal force pointing up. Mathematically, Work done= Force * Distance. 6-2-98 Energy gives us one more tool to use to approach physical situations. v2 = 64 – 2*9. The bigger unit of energy called kilowatt hour (kW h) Students learn the history of the waterwheel and common uses for water turbines today. v2 = 26. ] a Mark an appropriate scale on the axis labeled "Kinetic Energy (J). ) ii E k = 412 J [1] 1 × 20 × v 2 = 412 [1]; v ≈ 6. Exothermic reactions The diagram shows a reaction profile for an exothermic reaction. Examples are energy stored in a pile driver at the top of its path or energy stored in a coiled spring. These professionally crafted presentation templates for PowerPoint provide layouts for making presentations for energy themed topics. 75 m wide. Work and energy can be considered as two sides of the same coin. 1k plays . 4 J 39 Two elevators, A and B, move at constant speed. 3. Download PDF for free. This area represents the external work done by the ventricle to eject blood into the aorta. All NCERT textbook questions have been solved by our expert teachers. The change in the kinetic energy is equal to the amount of work done. Chapter 6: Work, Energy and Power Tuesday February 10th Reading: up to page 88 in the text book (Ch. 7. Unit: joules = watt-seconds or joule = Newton-meter: watt = joules/second: Common symbol(s) W: P: Example: I left a 60W light bulb on for 30 days, which raised my electric bill by 43. Calculate the work done by a 47 N force pushing a 0. In your physics class, you may be asked to interpret or draw an energy diagram. Or, When energy is transferred from one object to another, it appears as work and/or as heat. Energy at D = E + a1 – a2 + a3 Energy at E = E + a1 – a2 + a3 – a4 . when the external voltage is not applied to the device the Fermi level of metal and semiconductor are at same level. Different processes can produce the same state, but produce different amounts of work. 0 J. Label the vertical axis "Potential Energy" and the horizontal axis "Reaction Coordinate". Are able to define work and apply the definition to solve problems Revise how draw free body diagrams to find the components of forces Can state and apply the work energy theorem An enthalpy diagram plots information about a chemical reaction such as the starting energy level, how much energy needs to be added to activate the reaction, and the ending energy. Assume that a shuttlecock is smashed with 1600 J of work in 4. 20 Qs . Work is the amount of energy that is transferred while power is the rate or speed in which the energy is transferred at. The mass of the block is 10. We can determine lots of interesting things from this diagram. The work done by a force on an object to move it from point i to point f is opposite to the change in the potential energy: WU UU=−Δ =− −() f i In other words, if the work expended by the force is positive, the potential energy of the object is lowered. o, where K. Elastic potential energy = ½ kx2. Electromagnetic energy (or radiant energy) is energy from light or electromagnetic waves. Question 1. Whether you have laptops, iPads, chromebooks, or BYOD, your favorite PhET sims are always right at your fingertips. The initial energy is mgR (taking the dome level as the zero of the potential energy) Work is related to energy. 26 m. Compared to the gravitational potential energy on the top of the refrigerator, the cat's gravitational potential energy on top of the counter is During this step, the surroundings do work on the gas, pushing the piston down further (stage 4 figure, right), increasing its internal energy, compressing it, and causing its temperature to rise back to T h due solely to the work added to the system, but the entropy remains unchanged. d. However, that integral also represents the area under the curve on the pV diagram. Kinetic Energy. Work is the amount of energy that is transferred while power is the rate or speed in which the energy is transferred at. A Energy diagram Is a graph of energy that illustrates the process that occurs throughout a reaction. Therefore, we can say that the object has kinetic energy Answer: E. When we were analyzing situations in terms of forces and accelerations, we would usually freeze the action at a particular instant in time, draw a free-body diagram, set up force equations, figure out accelerations, etc. Which of the following forms? Of energy in the winds cause(s) the destruction? A. Sankey diagrams are a better way to illustrate which flows represent advantages and what flows are responsible for waste and emissions. 40. 2 Drawing free body diagrams 8 5. 2 kWh (kilowatt-hours). E. Based on your model calculate: the theoretical speed at which the marble reaches the bottom of your roller coaster track assuming no loss of mechanical energy. At this point the gas is in the same state as at the start It is a pressure (atm) multiplied by a volume (liter) so it must be some sort of work or energy. Energy. shown in the diagram below. S. Then we'll present diagrams and discuss photovoltaic solar,… Use the pV diagram to compare the work done: Since , work can be found by integrating the function with respect to volume (as you did in Part D). Work: A force that is exerted on an object that causes it to move through a distance. 4. 3 J (4) 0. newtons is used to pull back the string of a bow 0. Major photovoltaic system components. A Joule is the MKS metric unit for energy. The child is raised to point A and then released. Choose a coordinate system. The Sankey Diagram and Work When working with Sankey diagrams and physics, most physics Sankey diagram are use to examine energy efficincy. Work and Energy. Energy, Work, and Power Assessment Name: Date: 1. 3 m [1]Marking scheme Worksheet 1 Work done = force At position B, the kinetic energy of the car is _____ Joules and the total mechanical energy is ____ Joules. Check out network diagram examples to see the power of Creately. Work = E = F x. Energy (heat) is given out as bonds form in the products. energy diagram . 722. 722. I tried to attach it, but just in case it did not work the diagram has Position A at the top of the roller coaster with KE = 40,000 J and PE = 80,000 J. Note that ideal pendulum means that there is no energy lost to overcome air resistance and friction during oscillation. 3. This is the work energy theorem. Determine whether or not each force does work over the displacement in the diagram. A variation would be W = V(delta P), where V is volume, and delta P is the change in pressure. During this step, the surroundings do work on the gas, pushing the piston down further (stage 4 figure, right), increasing its internal energy, compressing it, and causing its temperature to rise back to T h due solely to the work added to the system, but the entropy remains unchanged. For example, if an apple is dropped from the branch of a tree, the force In this video, David shows how LOL diagrams allow us to visually represent what we mean by conservation of energy as well as what we mean by an energy system You can edit this template and create your own diagram. 2. From the free body diagram we have cosθ 2 cosθ 2 v Rg R mv FN −mg =− → = , where we have set FN = 0 when the pumpkin leaves the surface. 18 kJ in order to convert the value into kilocalories (1 kcal = 4. Energy associated with the state of motion of an object. Electrical energy (work input) is supplied from the wall outlet. Either of these interactions can affect the internal energy of the system. 3. Open systems. or ½ mv2. 92 × 10 3 , ∆E p = 1. Kinetic energy D. This calculation represents daily energy consumption. 5*m*v 2). workdone = 4. e. 0 seconds. The ball leaves the player’s hand at t= 0 s and reaches the basket at t = 3 s. 7-1 Work Done by a Constant Force Solving work problems: 1. Work & Energy review sheet 12. Learn to draw molecular orbital electron configuration energy diagrams. If we start with W = Fv²/2a and F = ma then we substitute F directly instead of a, and get W = mav²/2a instead. Power is the rate at which work is done, or energy is transmitted. By drawing a constant total energy on this plot, the difference between and is the radial kinetic energy, which must be positive. The free energy of a system changes during energy transfers such as chemical reactions, and this change is referred to as ∆G. e. The kinetic energy of the water is then converted into mechanical energy in a water turbine. 81*1. 4. 0 m to the right. 3 Calculations / solving problems 9 5. 1 = 412 J ≈ 410 J [1] (The work done = gain in gravitational potential energy. The energetic diagrams can also be defined as the visualization of an electronic configuration in orbitals; Each representation is an electron of an orbital with an arrow. Download free PDF of best NCERT Solutions , Class 9, Physics, CBSE- Work and Energy . a. Answer: Diagram shows a freely oscillating pendulum. f − K. 9. com Work and energy. Like Its "relatively Less Evil Twin," StrandHogg 2. 2. Practice Problems. 1. o is the original kinetic energy. Let the gravitational potential energy be zero before the spring is released. Energy is the capacity for doing work or supplying heat. Note that potential energy function includes an arbitrary additive constant, which means that the entire graph can be moved up or down on the vertical axis as much as one likes without changing the physical system at all. Download free PDF of best NCERT Solutions , Class 9, Physics, CBSE- Work and Energy . Answer. This approach assumes that you will be happy and fulfilled if you can find the right balance of attention for each of these dimensions. 3. A 2-kg object is being pushed by a horizontal force F along a horizontal frictionless air-table. Draw a series of energy pie charts for throwing a ball straight up in the air and catching it at the same level from which it was thrown. a Calculate the kinetic energy of the skateboarder at the bottom of the ramp. (7. 10-8-99 Sections 6. Let’s chose a 1D coordinate systemwith x-axis pointing upward. HW - Energy Diagram Worksheet 1. Work-energy theorem: Know the difference between conservative and non-conservative forces. I introduced the topic of work by stating that it represents one category of energy transfer to a system. Work Energy transferred “to” or “from” an object by means of a force acting on the object. Figure 3 show a basic diagram of a photovoltaic system and the relationship of individual components. Thus, the Carnot engine works like a refrigerator. A constant force is rare in the everyday world. workdone = 1/2 * 0. Kinetic energy of body moving with a certain velocity = work done on it to make it acquire that velocity Derivation Let an object of mass m , starts from rest and attains a uniform velocity v The overall change in energy in a reaction is the difference between the energy of the reactants and products. customary units are used, work and energy are expressed in ft. 2 2 If M is constant, the work is simply W 1−2 = M(θ2 − θ1). Energy resources included solar, nuclear, hydroelectric, wind, geothermal, natural gas, coal, biomass, and petroleum. The reaction shown by the second diagram is more exothermic. 0 m s -1 about to climb a ramp. So far I have set up my force diagram with my x-axis along the ground. Calculate the work done by a 2. q = heat = energy transferred from a hotter object to a colder one w = work = energy used to cause an object to move against a force That means, we can change the energy of the system by applying heat and doing work. When external voltage is applied to device it behaves according to the voltage applied with respect to flat band voltage and threshold voltage. Potential energy, also referred to as stored energy, is the ability of a system to do work due to its position or internal structure. (ii) Potential energy of the spring is imparted to the ball in the form of kinetic energy. Energy at B = E + a1 Energy at C = E + a1– a2 . At this point the gas is in the same state as at the start Living cells depend on the harvesting of potential energy from molecular bonds to perform work. 1 Key concepts 8 5. 93-kg cat jumping from the top of a 1. Work, Power And Energy Class 9 Extra Questions Short Answer Questions-II. At which point does the ball have the maximum kinetic energy? Energy, Work, and Power . In this figure, we show orbits with a given angular momentum and four generic total energies . With these templates you can cover a wide range of topics related to mobile devices and battery life, green energy, energy efficient modes of production, global warming, energy consumption, engineering, etc. 008 metres), then we will determine the work Ben has done. For example, in the operation of a commercial heat pump, the thermal energy transferred to the inside of the building (Q h) was found to be 80 kJ, whereas the thermal energy extracted from the cold outside air was 60 kJ. 8-meter-high counter. The net Work being done on the block is negative. Work is said to be done when the force is applied on a body and the body covers a certain distance. 6) •Finish Newton’s laws and circular motion •Energy • Work (definition) • Examples of work •Work and Kinetic Energy •Conservative and non-conservative forces •Work and Potential Energy •Conservation of Energy These diagrams are showing how pistons in engines (powered by fuel) or the various processes in a power plant, change the volume and pressure of a working fluid (ex. As long as the energy lost (by the gas doing work) equals the heat gained from the water, the internal energy will not change and the temperature stays the same. W = 60 J: Joule is abbreviated J. The green arrow is longer. Work, Energy and Power – page 2 22. Stroke work is sometimes used to assess ventricular function. 2. Note that if the displacement is zero, the work is zero, even if a force is applied. Work-Energy Theorem Draw a free-body diagram for each force on the object. Mathematically, Energy = mass x gravity x Work and the work-energy theorem Mech HW-48 An object moves clockwise along the trajectory shown in the top-view diagram below acceleration varies, but is always directed toward point K. Therefore, we have proved the Work-Energy Theorem. We will first discuss the relationship between the real work done by kinetic friction on a deformable body and the calculation that we can perform using the work-kinetic energy theorem to determine the change in the mechanical energy due to kinetic friction. ). Mathematically, Power= Work done/time taken. Draw energy diagrams for these states including: 1) Choice of zero point P for potential energy for each interaction in which potential energy difference is well-defined. Car A and car B of equal mass travel up a hill. e. It gains energy (E > 0) when H 2 O is decomposed into H 2 and O 2. Compare the areas under the isobaric and isothermal curves to determine in which case more work is done. How Do All-Electric Cars Work? All-electric vehicles (EVs), also referred to as battery electric vehicles, have an electric motor instead of an internal combustion engine. If U. Be sure to include rotational kinetic energy in your calculation. Mirrors at both ends of the glass amplifier cause the photons to travel back and forth through the glass, stimulating more electrons to drop to their lower energy states and emit photons. The vehicle uses a large traction battery pack to power the electric motor and must be plugged in to a wall outlet or charging equipment , also called electric vehicle supply Evil Twin Attack Android No Root With This Level Of Access, An Intruder Can Proceed To Upload Data From A Victim's Device. com Construction of an energy diagram entails first graphing the potential energy function for the conservative force on the axes. For convenience move the start of the cycle to point A. The work done by a nonconservative force can be expressed W NC = (ΔKE) + (ΔPE) FACT: The work done on an object by a net force equals the change in kinetic energy of the object: W = KE f - KE i. The energy of an object can never be zero. Most movements in basketball that involve a force can be expressed through work, power, and/or energy. Since the problem involves a change in height and speed, we make use of the generalized WorkEnergy Theorem, This is the molecular orbital diagram for the homonuclear diatomic Be2+, . Theory: In Chapter 7 of your textbook, there are a couple of different formulas that may be called “work - energy theorems,” depending on the context. Solar Energy Diagram #5 – Concentrated Solar Power (CSP) Concentrated solar power, or CSP, works by using an array of lenses or mirrors to focus a large area of sunlight (solar thermal energy) onto a small area. Power P= work done/ time taken = 50*10*25 J/ 5s = 2500 W. i do not know how to do this, as this is a pV diagram and these paths are not further The work-energy theorem (W = Delta KE) will be used to analyze each part. a. If heat were added at a constant rate to a mass of ice to take it through its phase changes to liquid water and then to steam, the energies required to accomplish the phase changes (called the latent heat of fusion and latent heat of vaporization) would Substituting for energy e in the above energy equation and simplifying, we obtain the final form of the energy equation for a single-inlet single-outlet steady flow control volume as follows: Notice that enthalpy h is fundamental to the energy equation for a control volume. The net Work being done on the box decreases its kinetic energy K. 25 m. In order to do this work energy had to be transferred. We will define work done by a force as: work done by a force = amount of force along direction of motion × distance moved. The energy diagram for a typical one-step reaction might look like this: Work done in diagram I = mgh. Energy is the capacity to do work. 34 × 10 3 J; 60 × 9. Understand the difference of positive, negative and no work done. Phase changes Transitions between solid, liquid, and gaseous phases typically involve large amounts of energy compared to the specific heat. Assume no friction. Because the temperature change is the same, the change in internal Consider the Torque angle diagram again. 3. Work and Energy Goals •To apply the concept of work to each of the forces acting on an object pulled up an incline at constant speed. Draw a line segment that represents the potential energy of the reactants and label the line Work, Energy and Power Practice Test 1 In the accompanying diagram, an average force of 20. From position A to position B, Pete is pushing the mug and the net force upon the mug is simply the applied force minus the friction force (see free-body diagram below). Examples, including Bernouilli's law. Work, energy and power. • Power = Work or Energy / Time • P = W/t = F x d/t = F v • The unit joule is too small . Indicate in your diagram how the total mechanical energy in it remains constant during the oscillation. 001 m 3 / 1 l ] [ 1. twice as much C. 3. Draw and label the activation Students analyze a diagram showing how the energy obtained from a resource gets to homes to power a light bulb. A 2kg crate rests on the floor. Two of the main types of mechanical energy are kinetic and potential. The ability to do work. This diagram suggests that the energy of an H 2 molecule is lower than that of a pair of isolated atoms. Activity 14 Work and Energy for Systems Objective: To practice drawing and interpreting work-energy diagrams and understand how the diagram depends on the choice of system. Rates vs Amounts Chemical processes use process streams to transport material from one point to another. Recommended: Short note on work, energy and power. The net work comes from the work done during the downward motion by gravity. f is the final kinetic energy and K. Therefore, doing positive work will result in an increase of kinetic energy. g sandwich across a table 0. For an open system, the first law of thermodynamics admits three forms of energy transfer, as work, as heat, and as energy associated with matter that is transferred. Unit: joules = watt-seconds or joule = Newton-meter: watt = joules/second: Common symbol(s) W: P: Example: I left a 60W light bulb on for 30 days, which raised my electric bill by 43. 4, we have . 0 seconds. the same B. This was created as part of my Senior Exit. 3. The Work being done by the applied force is negative. Use the work-energy theorem to ﬁnd (a) the speed of the hammerhead just as it heats the I-beam and (b) the average force the hammerhead exerts on the I-beam. Is work a state function? Provide two examples of a system undergoing work interactions with its surroundings. 92 × 10 3 J ≈ 1. and, hence, the total work done by a couple is zero. 5. An optical switch traps the low-energy laser pulse in the main amplifier for four passes through the laser glass slabs. 4 Energy gives us one more tool to use to analyze physical situations. Kinetic energy = ½ mv2. r m; this unit is called, a joule (J. When a car skids to a stop, the work done by friction upon the car is equal to the change in kinetic energy of the car. Potential energy The energy band diagrams of semiconductors are rather complex. Write down these dimensions on the diagram, one on each spoke of the life wheel. A Sankey diagram is a graphic illustration of flows, like energy, material or money flows. Heat is sucked out of the cold reservoir that is present inside a fridge. 03 J (2) 0. Center of Mass Pseudo-Work. Power can be modeled by the equation: P= W/ Δt, where 'P' is the power, 'W' is work and 't' is time. lb. Work and Energy 1. Work: It is defined as the product of force applied and the distance moved by the body on the application of the force Sketch a diagram of your roller coaster, label the dimensions of your coaster on the diagram. 2: The student is able to apply the concepts of Conservation of Energy and the Work-Energy theorem to determine qualitatively and/or quantitatively that work done on a two-object system in linear motion will change the kinetic energy of the center of mass of the system, the potential energy of the systems, and/or the internal energy of Energy:The ability to do work;work. Mathematically, Work done= Force * Distance. As such, work is energy transfer work. 2 Draw a labelled free-body diagram showing ALL the forces acting on the soldier while being lifted upwards. As we noted in Section 5. 5 atm-l [ 0. It measures how fast energy is being used. The usable energy stored in the battery as chemical energy becomes degraded energy when Energy: An entity that makes matter move. The energy band diagrams contain multiple completely-filled and completely-empty bands. W = 253 J The change of energy from one form to another takes place in such a way that a part of energy assumes waste form (heat energy). Energy. Ignore eﬀects of air. Usually the flows are illustrated as arrows. Calculate the actual work done using the change in kinetic energy for each trial. 1. 025 kg pencil 0. Question. Calculate the work done by a 47 N force pushing a pencil 0. Energy Diagrams Identify system Identify state of system before interaction and state of final states. A moving object is capable of doing work because of its motion. 7: The area of the rectangular region under the 1to 2 process is the work done by the Physics 1120 In-Class Problems: Work & Energy Energy. Which letter indicates the potential energy of the activated complex? __c____ 3. The diagram below shows the path of a student on a sled starting from rest at point W. 3: Work done by a gas) Figure 15. Derive the theorem using (a) a non-calculus approach: Assume a constant F net acts through a distance x. The capacity of doing work is called energy. Illustrate your answer with the help of a labelled diagram. However, that integral also represents the area under the curve on the pV diagram. netis the magnitude of the constant force, ∆d is the magnitude of the displacement of the object, and θ is the angle between the direction of the force and the displacement. Mathematically, Energy = mass x gravity x height. Work done in raising 50kg water to a height of 25m against the force of gravity is: W = mg x h= mgh. Going from the top of the curve to the products, we are going down the energy axis of the graph. 20 kg, and the height h of the hill is 5. four times as much 13. Find the work done by frictinoal force on upper block and on the lower block t = 2s. E. 29. g. 2. But when using the idea of work consider the Input energy to Input work (it turns out to be the exact same thing units and all) and the useful output energy to output work. The car leaves point A with no initial velocity and travels to other points along the track. Energy Flow Diagrams (often also referred to as Energy Flow Charts) are used to show energy and energy transformation visually and quantitatively. The zero energy level is taken as the energy of point A. The diagram below shows the path of a student on a sled starting from rest at point W. Take for example a 1. This relationship is called the work-energy theorem. 2:. In the diagram, 55 joules of work Potential Energy Diagrams The energy changes that occur during a chemical reaction can be shown in a diagram called a potential energy diagram, or sometimes called a reaction progress curve. Energy transfer and power as the rate of doing work. d. Work done can be zero. Be sure to include rotational kinetic energy in your calculation. They describe the process by which electricity gets from its source to its destination, track and graph how much energy is transferred out of the system at each step, and write a statement about energy based on what they have learned. Kinetic is when an object is at motion and potential is when the object is at rest. In this way, after transformation the capacity of energy to perform work is decreased. The confusion of work and power is much anticipated but they are two different things. Power is the rate at which work is done, or energy is transmitted. Assess Each Area. weight pointing down. Uses electrical energy to do work • Mechanical Power Uses mechanical energy to do work (linear, rotary) • Fluid Power Uses energy transferred by liquids (hydraulic) and gases (pneumatic) • Power is the rate that we use energy. Step 3: Apply the work-energy Work and Energy Diagram Skills Conservation of Energy A roller-coaster car with a mass of m moves along a smooth track as diagrammed in the graph below. The accompanying diagram shows block A, having mass 2m and speed v, and block B having mass m and speed 2v. Physics with animations and video film clips. Newton's second law and the work-energy theorem. However, it is usually not done that way. Kinetic energy is energy of motion, while potential energy is stored energy. The student slides down a frictionless, snow-covered hill past Analysis: Work Energy 1. There is an increase in internal energy due to friction. A short lesson on kinetic energy and work in single-object systems geared toward Honors Physics students. 79 J/( o C mole) which fills a balloon at STP (standard temperature and pressure Finally (11) we can see that work equal kinetic energy. What is the kinetic energy of the cart when it reaches the top of the next hill, having height h2? (1)mgh1 (3)Mg(h2-h3) (2)Mg(h1-h2) (4)0 15. Gravitational potential energy = mgh. 0 kg object along a rough floor at a constant speed of 2. 3. Work done is generally referred in relation to the force applied while energy is used in reference to other factors such as heat. The zero energy level is taken as the energy of point A. c. An energy diagram shows how the potential energy of […] Work, EnErgy & PoWEr Study the sample problems on pages 76, 80, & 82 and answer the “Now it’s your turn” questions. Simpler Solution (Edit) When reading through this post by chance again I noticed my approach could have been a lot simpler. Then a is easily eliminated and we end up with W Work and Energy-Basic . Take for example a 1. Two kinds of work are normally associated with a chemical reaction: electrical work and work of expansion. The positive work done by the non-conservative force is cancelled by the fact that exactly the same amount of negative work is done by gravity. Looks like the unit for energy transferred, and thus, the unit for energy, is Newton-meter. Year 8 Science - Energy Flow Diagrams An energy flow diagram is a visual way to show the uses of energy in a system. Work, heat, and changes in internal energy can also be determined. Use PDF export for high quality prints and SVG export for large sharp images or embed your diagrams anywhere with the Creately viewer. It can only change from one form to another. Examples are energy stored in a pile driver at the top of its path or energy stored in a coiled spring. 2. Chemical reactions can do work on their surroundings by driving an electric current through an external wire. The forces are the tension of the string and the weight (if it is subject to the gravity of the Earth). Figure 3 By definition of a mean value, the red area A 1 must be equal to the blue area A 2. 1. The Work-Energy Theorem. Work is directly proportional to the displacement of the car (skidding distance) and the kinetic energy is directly related to the square of the speed (KE=0. Let the energy at A be EA. Answer. Difference Between Work and Energy. Draw a free body diagram showing all forces acting on the air cart, including the extra Use the pV diagram to compare the work done: Since , work can be found by integrating the function with respect to volume (as you did in Part D). 1 J (3) 0. The work simplification indicate that change and improvement in work methods are necessary in every home. Energy . The mass of the child is 35 kg. See full list on mathsisfun. A basketball is thrown into the basket, as shown in the diagram. A unit of Energy is the Joule. Interpreting a one-dimensional potential energy diagram allows you to obtain qualitative, and some quantitative, information about the motion of a particle. 7E k = 0. 6 eV 1s F –18. The work/energy principles discussed here are identical to electric work/energy principles. 6k plays . Work and Power. Proving the Work-Energy Theorem for a variable force is a little tricky. Furthermore, the system either does work on it surroundings or has work done on it by its surroundings. : a) The Energy Equation for Closed Systems. Potential energy. The work done on a system can also be converted into Work: A practical way to calculate the work done by a gas in a particular thermodynamic process is to find the area under the curve for that process on the P-V diagram. Lab 6. Thus, energy flows from higher to lower level. The F 2s is nonbonding. Energy is the capacity to do work. The reactants are higher up the The energy from nuclear fission can be converted into electrical energy, thermal energy, and mechanical energy. a. Stated quantitatively: ! W = "K = mv 2 2 2 - mv 1 2 (1) Equation 1 is a Using the symbols from the diagram, this reduces to: Q h = Q c + W. Where the sun can energise photovoltaic panels for a variable handful of hours a day and the wind can blow turbines for days on end but equally disappear for extended periods without warning, the tide is near constant and entirely predictable. How much work is required to move it at constant speed a) 3m along the floor against a friction force of 4N, b) 3m along a frictionless air table, c) 3m vertically? 2. Work done by conservative forces Work done by conservative forces , or path-independent forces, results in changes in the object's potential energy. All NCERT textbook questions have been solved by our expert teachers. Work, Power and Energy Worksheet. Calculate the speed of the mass at 10. The width of the arrows is proportional to the size of the represented flow. [1] b i W = Fx, F = weight = mg = 20 × 9. Energy is defined as the capacity to do work. A force of 5. Notation: – W (kJ) amount of work transfer – W° (kW) power Q = 5 kJ Q = ‐ 5 kJ Heat in System Heat out The confusion of work and power is much anticipated but they are two different things. com Work and Energy - Potential energy diagram Problem Statement: The potential energy of a particle of mass m is represented in the figure below as a function of its position r. At a turning point, the potential energy equals the mechanical energy and the kinetic energy is zero, indicating that the direction of the velocity reverses there. 5 Calculating the net work done on an object 10 5. •To compare the total work on an object to the change in its kinetic energy as a ﬁrst step in the application of the so-called Work-Energy Theorem. The Work done on an object is equal to the change in its kinetic energy. electrons would be in a bonding orbital, we would predict the Li2 molecule to be . Thus, if SI metric units are used, wok and energy are expressed in N. Thus energy is transferred between the system and the surroundings in the form of heat and work, resulting in a change of internal energy of the system. E. According to Mundel there are five levels of changes that can improve one’s method of work: 1. Car A moves up the hill at a constant speed that is twice the constant speed of car B. Work = F. Work - definition Work is defined as the force in the direction of displacement times displacement. Main source of energy is sun. E sys = q + w. Energy is power integrated over time. To achieve this, the amount of electrical work (W) needed Hydroelectric power plant (Hydel plant) utilizes the potential energy of water stored in a dam built across the river. The engine can be acted upon by an external force to transfer heat. steam water for turbines, fuel-air mixture for engines) to create work. 3 * 26. In this article, we will look at all of the equipment that brings electrical power to your home and what kinds of glitches can cause a blackout. Be sure to keep any positive or negative signs in the work done. As a block is accelerated from rest along a horizontal surface, its gravitational potential energy (1)decreases (3)remains the same This relationship is called the work‐energy theorem: W net = K. Then, is the potential energy due to the spring, is the potential Use work and energy to find Paul's speed after being pulled 2. Assess Each Area. Compared to the power developed by car B, the power developed by car A is A. cycle repeats after G) the system’s kinetic energy. fr = = = = × × ° = = = × × ° = θ θ W F x W F x m P P N F F g r r r Copyright © 2009 Pearson Education, Inc. Work and work-energy theorem: 1. Heat energy B. The block is slowing down. Pressure-volume graphs are used to describe thermodynamic processes — especially for gases. Question 3 Text in this Example: House Electricity Grid The high-voltage transmission systems carry electricity from the power plants and transmit it hundreds of miles away, and the lower-voltage distribution systems draw electricity from the transmission lines and distribute it to individual customers Wind Energy Transformer Substation Wind Turbines The wind turns the blades, which spin a shaft, which Strain energy = 1 0 x U Pdx i =∫ Work and energy should be expressed in units obtained by multiplying units of length by units of force. The work done in accelerating an object along a frictionless horizontal surface is equal to the object's change in (1)momentum (3)potential energy (2)velocity (4)kinetic energy Calculations done on the net work done on an object. molecular orbital electron configuration diagram for Li2 (Figure “Molecular orbital. 79 J/( o C mole) which fills a balloon at STP (standard temperature and pressure performed net work on the system so as to increase the system’s energy. 25 m against a force of 23 N. Abstract: Energy flow diagrams offer an excellent pedagogical approach to processes of all sorts. (a) Kinetic energy -Law of conservation of energy states that energy can never be created or destroyed. At this point the gas is in the same state as at the start Work, Power, Energy and Society are all components found in forms of movement that pertain to forces. Each template Kinetic Energy vs Time 30 o 24 6 81012 Time (s) Compare the speed of the mass at 6. Sketch a diagram of your roller coaster, label the dimensions of your coaster on the diagram. and force susan to the right. 4 Distinguish between work, energy and power. net ∆d cos θ, where F. Support for many network diagram types including Amazon web service diagrams; Smart objects that reacts to other objects; Real-time collaboration to work with peers By converting our sims to HTML5, we make them seamlessly available across platforms and devices. 7 Work-energy theorem 11 As a result, a portion of endothermic heat energy input into a system is not deposited as internal energy, but is returned to the surroundings as expansion work. 0. If a ball rises to a height of h =10 m Work and Energy:Wexternal= ΔEsystem Consider a 0. 2. As a result, the H 2 molecule is more stable than a pair of isolated atoms. hi i have this pV-diagram(ideal gas) and i am supposed to say something about the heat, internal energy and work transferred and done on these different paths( i have to bring them in an order like). Write These Down on the Wheel. The student slides down a frictionless, snow-covered hill past Kinetic energy of body moving with a certain velocity = work done on it to make it acquire that velocity Derivation Let an object of mass m , starts from rest and attains a uniform velocity v The work simplification indicate that change and improvement in work methods are necessary in every home. . 50-kg block travelling at 2. What is tidal energy and how does it work? The tide is renewable and relentless. Which letter indicates the activation It can also be defined as the rate of change of energy. Most CSP systems work by heating up water which, in the form of steam, drives a steam turbine and produces electrical power. Draw the energy level diagram. Sol. See full list on courses. Using the Molecular Orbital Model to Explain Why Some Molecules Do Not Exist Stroke work is best depicted by the use of ventricular pressure-volume diagrams, in which stroke work is the area within the pressure-volume loop. W = 60 Joules: Energy units are called Joules, 1 Joule is equal to 1 Newton-meter. Draw a free-body diagram. 4 N force pushing a 400. [Show all work, includino the equation arid substitution with units. Rate of doing work is called power. Activity 14 Work and Energy for Systems Objective: To practice drawing and interpreting work-energy diagrams and understand how the diagram depends on the choice of system. 0 Is Work is done (i) by horizontal component of (a) and are perpendicu lar to displaceme nt so they do no work. The first law, which deals with changes in the internal energy, thus becomes 0 = Q - W, so Q = W. Once you have the potential energy diagram for a situation, you can describe the motion of an object. A and B are the points where the diagram passes through the mean. 0 N moves a 6. 5 m/s. The work done by the gas in this process is the area under the curve on the P-V diagram. Light energy C. Question 9: Draw a diagram to show the energy changes in an oscillating simple pendulum. State the SI units for each of these quantities. Work refers to the force and direction of movement of a force, energy is the capacity to do work and power is the rate at which energy is transformed or the rate at which work is done. Work, Energy And Power Details with Diagram Click Here To Download the Note Work, Energy And Power Details with Diagram Work: Work refers to an activity involving a force and movement in the directon of the force. There is a greater difference in energy between the reactants and products. 980 joules of chemical energy from food eaten by the weight lifter was transferred to 980 joules of gravitational potential energy to the barbell. half as much D. A single energy flow chart depicting resources and their use represents vast quantities of data. Conservative forces, non-conservative forces and the definition of potential energy. The potential energy of the stored water is converted into kinetic energy by first passing it through the penstock pipe. 18 kJ). W = area under the curve on the P-V diagram. There is a diagram with this problem. 00 mole sample of argon gas having a molar constant pressure heat capacity of 20. tension to the left. When forces and accelerations are used, you usually freeze the action at a particular instant in time, draw a free-body diagram, set up force equations, figure out accelerations, etc. lumenlearning. " Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero. 9 × 10 3 J [1] 2 b ∆E p = 0. Home makers who want to simplify their tasks can easily do so by making a careful study of their methods of work. As a result, a portion of endothermic heat energy input into a system is not deposited as internal energy, but is returned to the surroundings as expansion work. Free energy is a measure of energy that is available to do work. The thermodynamic cycle that is observed in the Carnot engine is a reversible process. 10 5. 278. (b) Explain how, the total energy a swinging pendulum at any instant of time remains conserved. Work, energy and power 8 5. the direction of the velocity of the object, and the direction of the net force on the To become familiar with work, power, and kinetic energy and the relationship between each of them. During this step, the surroundings do work on the gas, pushing the piston down further (stage 4 figure, right), increasing its internal energy, compressing it, and causing its temperature to rise back to T h due solely to the work added to the system, but the entropy remains unchanged. It can also be defined as the rate of change of energy. In other words, the couples do work which results in the kinetic energy of rotation. WORK ENERGY POWER 01 JULY 2014 Check List Make sure you …. 1) 2 K 1 mv2 Units: 1 Joule = 1J = 1 kgm2/s2 = N m II. These diagrams can be useful in describing motion for all types of objects. 60 m. 2 eV 2s 2p So H–F has one σ bond and three lone electron pairs on fluorine Glycolysis : All Steps with Diagram, Enzymes, Products, Energy Yield and Significance By Editorial Team on January 4, 2020 in Biochemistry Glycolysis is derived from the Greek words ( glykys = sweet and lysis = splitting ). Work has units of energy (e. 0 seconds. If Ben applies a force of 1050N on a football that travels 70 yards (64. How much work must be done to stop an 1 800 kg vehicle travelling at 30 m/s? Circle the letter next to each sentence that is true about energy. 60 m As the arrow leaves the bow, its kinetic energy is 39. Theory: If an amount of work, W, is done on a system, then the kinetic energy, K, of the system changes. In order to find the angle we need to use conservation of energy: 2 cosθ 2 mgR =1 mv +mgR. 2 kWh (kilowatt-hours). 1. Potential Energy Diagram Worksheet ANSWERS 1. 2. You can also get free sample papers, Notes, Important Questions. Overview of Work Energy Power 5 5. A boulder has more potential energy when it’s at the top of a hill than when it’s rolling down. 9. Work done by gravity depends on the differences in vertical heights of the initial and final positions of the object and not on the path along which the object is moved. C. chance to take on “the big one”: to investigate the validity of the work-energy theorem. On the other hand, if the body experiences a rotation dθ, then the work done by the couple is a a dW = F dθ + F dθ = F adθ = Mdθ . J, cal, BTU). It is an exothermic / endothermic (circle one) reaction and its energy is positive / negative (circle one). b. Part 1: Work and Power Let’s define two quantities, work and power, that will be useful for explaining the motion of objects. Gasoline contains a significant amount of chemical potential energy. Q14 the WorkEnergy Theorem: , where is the final energy, is the initial energy, and is the work done on the system by external forces. I want to talk to you about Lowell diagrams that's right I said Lowell diagrams these are a great way to visualize conservation of energy and even better they force you to think about what's part of your energy system and what isn't part of your energy system and if you don't know what an energy system is maybe that's where we should start an energy system is an object or a collection of Work and energy. workdone by a net force = change in kinetic energy of a body. Drawing of force diagrams to determine the net work done on an object - Ignore perpendicular forces. From the equation below you can see that. Now, this is just a units conversion question, W = 2. Work and Energy Diagram Skills Conservation of Energy A roller-coaster car with a mass of m moves along a smooth track as diagrammed in the graph below. According to Mundel there are five levels of changes that can improve one’s method of work: 1. Assume that a shuttlecock is smashed Download Energy PowerPoint Templates. Which of the letters a–f in the diagram represents the potential energy of the products? ___e__ 2. May 13, 2011 Energy Transfer, PE, KE and Efficiency Work • Definition: – A measure of the change a force produces: – “The work done by a force acting on an object is equal to the magnitude of the Volume of water= 50 L=50 x 10 -3 m 3. 0 seconds to the speed of the mass at 10. Energy at F = E + a 1 – a2 + a3 – a4 + a5 Energy at G = E + a1 – a2 + a3 – a4 + a5 – a6 = Energy at A (i. The work done on an object by a net (resultant) force is equal to the change in the object's kinetic energy. This shows how energy is converted from one form into another. Is the magnitude of work done by the frictional force on upper and lower blocks same? c. Draw and label arrows on the diagram at points A-G to indicate: a. Notice that not only does the work done by the gas depend on the process, but also the heat transferred to the gas. 0 2 [1]; E k = 1. Step 2: Draw a free-body diagram. 6 Summary of two methods of determining the net work done. 0 kg. The principle of work and kinetic energy (also known as the work-energy theorem) states that the work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle. January 16, 2020 January 19, 2020 | O Level, Work, Energy & Power Consider an ideal pendulum (as shown in the diagram below). These orbits have the following characteristics and names: Work done = 490 x 2 = 980 Joules In the above example, the work done by the weight lifter in lifting the weights was 980 joules. Potential energy is measured in units of joules. • The line is called an isotherm, because the temperature stayed the same. At point B the energy has increased by an amount equal to A 1. • unit: J Work Energy Theorem: The work done is equal to the change in the kinetic energy: ∆K = K f − K i = W In the above example with the ball falling from a height of h = 10 m, the work done by gravity: W = ∆k = k f − ki = 294 J − 0 J = 294 J. b. See full list on physicsclassroom. 34 × 10 3 J [1] mg∆h = 1. 1, any system can exchange energy with its surroundings in two general ways: as heat or as work. Power: The rate at which work is done on an object (or the rate at which energy is transformed). 81 × ∆h = 1. 3. 60 meter. Gravitational potential energy is energy of diagram for questions 10 and 11. This approach assumes that you will be happy and fulfilled if you can find the right balance of attention for each of these dimensions. W stands for work, P is the pressure of the system (for gases), and delta V is the change in volume for the system. The car leaves point A with no initial velocity and travels to other points along the track. b. A potential energy diagram shows the change in potential energy of a system as reactants are converted into products. What is the car’s kinetic energy at Start studying Work, Power, Simple Machines, Energy and Motion. MO Diagram for HF The AO energies suggest that the 1s orbital of hydrogen interacts mostly with a 2p orbital of fluorine. This definition can be extended to rigid bodies by defining the work of the torque and rotational kinetic energy. This paper proceeds from simple processes to complex socially significant processes such as global warming. 00 mole sample of argon gas having a molar constant pressure heat capacity of 20. These formulas show that work is the energy associated with the action of a force, so work subsequently possesses the physical dimensions, and units, of energy. In order for a mass to lose kinetic energy, negative work must be done on the mass to slow it down. Energy Transfer Work vs. It represents amount of energy transferred. Thermodynamic work does not account for any energy transferred between systems as heat or through transfer of matter. Physics . Look at the diagram. Energy, Work, and Power Assessment Name: Date: 1. Example: Any form of light has electromagnetic energy , including parts of the spectrum we can't see. 34 × 10 3 [1] ∆h ≈ 2. Work and Potential Energy A) Overview This unit is concerned with two topics. Home makers who want to simplify their tasks can easily do so by making a careful study of their methods of work. They explore kinetic energy by creating their own experimental waterwheel from a two-liter plastic bottle. Which of the following graphs best represents the ball’s kinetic energy Ek as a function of time? 2. Mass of water= Volume of water x density of water. 1 - 6. a. It's important to differentiate among the different types of solar energy production systems since it's not uncommon for the average homeowner to confuse them. At the instant shown, there is a rope with a tension of 1. Workdone Under a Variable Force. Density of water= 1000 kgm -3. 1. 013 x 10 5 Pa / 1 atm ] W = 253 Pa-m 3 [ (N/m 2) / Pa ] W = 253 N-m. 81 ≈ 196 N [1] W = 196 × 2. The energy is plotted as a function of the wavenumber, k, along the main crystallographic directions in the crystal, since the band diagram depends on the direction in the crystal. On the other hand, there are is only one type of work. In an energy diagram, the vertical axis represents the overall energy of the reactants, while the horizontal axis is the ‘reaction coordinate’, tracing from left to right the progress of the reaction from starting compounds to final products. Students also In thermodynamics and engineering, a heat engine is a system that converts heat or thermal energy to mechanical energy, which can then be used to do mechanical work. Using the energy curve below label and answer the following questions. Power can be modeled by the equation: P= W/ Δt, where 'P' is the power, 'W' is work and 't' is time. Check your answers against the answers from the book. You can also get free sample papers, Notes, Important Questions. 4 m s -1 [1] 2 E k = 1 × 60 × 8. c. Adiabatic processes DIRECTIONS: On the basis of following diagram/ picture answer the questions given below: In many parts of the world, strong winds cause a lot of destruction. MOS capacitor is an equilibrium device i. Energy flow diagrams change over time as new technologies are developed and as priorities change. A simple diagram for the energy flow in a mobile phone is shown below. lb or in. In each The diagram above shows a 1. Write down these dimensions on the diagram, one on each spoke of the life wheel. (Equation 15. Compare the areas under the isobaric and isothermal curves to determine in which case more work is done. A is the correct option. An enthalpy Network topology diagrams, CISCO diagrams, data center diagrams & more. This energy can come in many forms. They picture energy transformations in an accurate, quantitative, and conceptually transparent manner. We consider the First Law of Thermodynamics applied to stationary closed systems as a conservation of energy principle. Apply Newton’s laws to determine any • both kinetic energy and work are scalars. A variable force is what we encounter in our daily life. Radio, gamma rays , x-rays, microwaves, and ultraviolet light are some examples of electromagnetic energy. A catalyst can work by lowering the activation energy for a reaction. Both these quantities are measured in joules. 0 N attached while the block travels 1. Conservation of mechanical energy. workdone = 1/2 m v2. There is a quantity that is calculated in much the same way as work, with one subtle difference. 1-kilogram hamburger vertically upward at constant velocity 0. The detailed energy band diagrams of germanium, silicon and gallium arsenide are shown in Figure 2. [3] 3 The diagram shows a 60 kg skateboarder travelling at a speed of 8. 2m 2v Frictionless Step 1 – Find the work done in this process. 2. Because the pressure is constant we can use Equation 15. The energy band diagram contains the electron energy levels in the MOS structure as deliniated with the fermi energy in the metal and semiconductor as well as the conduction and valence band Q. 16. More specifically, work is the energy transfer associated with force acting through a distance. The usual method of using potential energy diagrams is to: • start with the physical situation • use the physics to draw the potential energy diagram Note that since the satellite's speed and orbital radius remain constant, no energy is being changed; therefore, no work is being done on the satellite. Figure 1. Heat is energy that transfers from one object to another because they are at the same temperature. We'll start with a diagram of solar energy hitting the earth surface. Then this work can be used to create electricity or move a vehicle. Is the work done by the frictional force on the upper block converted to heat or mechanical energy or both? The smart grid project also will extend the reach of the grid to access remote sources of renewable energy like geothermal power and wind farms [source: DOE]. There are basically several types of energy such as potential, kinetic or nuclear energy, solar energy or electrical energy, etc. Relating E to Heat and Work. The work and energy plots can be examined to note the total work done and change in kinetic energy of the box. In order for a mass to gain kinetic energy, positive work must be done on the mass to push it up to a certain speed. If you use 1 Watt for 1 hour you just multiply (1W • 1H= 1Wh) or (1 joule/1 second • 3600 second = 3600 Joules) 1 WH=3600 Joules=Enegy Solution: We will start by drawing the forces acting on the mass of the pendulum at any point of its trajectory. The activation energy is the minimum amount of energy needed for the reaction to occur. 4. H–F nb σ σ* Energy H –13. Work, EnErgy & PoWEr The diagram shows a child on a swing. If the velocity of a moving object is doubled, the object's kinetic energy is (1)unchanged (3)doubled (2)halved (4)quadrupled 2. 7 × 1. head. U=Q W U=−W W U=0 The PV diagram we get shows a curved line as the pressure and volume both change. v2 = 64 – 37. 2) Draw speed of all objects in system Work. This may include primary energy used as raw fuels to feed into a system, energy supply, conversion or transformation, losses and energy being used. In addition, an assortment of balance of system (BOS) hardware, including wiring, overcurrent, surge protection and disconnect devices, and other power processing equipment. Summary Because the net force on a particle is equal to its mass times the derivative of its velocity, the integral for the net work done on the particle is equal to the change in the particle’s kinetic energy. It takes energy to do the work. It is a scalar Potential energy, also referred to as stored energy, is the ability of a system to do work due to its position or internal structure. work and energy diagram