Class 9 Science Worksheet For Work And Power. This is the process heat, which involves work on the molecular scale. When you do work to move an object, you change the objects energy. A person in good physical condition can put out 100 W of useful power for several hours at a stretch, perhaps by pedaling a mechanism that drives an electric generator. Kinetic energy depends on the mass of an object and its velocity, v. When we drop the rock the force of gravity causes the rock to fall, giving the rock kinetic energy. Solution If we drop the rock, the force of gravity increases the rocks kinetic energy as the rock moves downward until it hits the ground. Under what conditions would it lose energy? Advanced search. (c) Calculate the mass of food that had to be supplied each day, assuming that the average worker required 3600 kcal per day and that their diet was 5% protein, 60% carbohydrate, and 35% fat. This theorem was proposed and successfully tested by James Joule, shown in Figure 9.2. In the diagram below, the spring has a force constant of 5000 N/m, the block has a mass of 6.20 kg, and the height h of the hill is 5.25 m. Determine the compression of the spring such that the block just makes it to the top of the hill. The questions must be done in the We have Provided Work and Energy Class 9 Science MCQs Questions with Answers to help students understand the concept very well. 41. Recall from the laws of motion that force is not required to move an object at constant velocity. What are the harmful impacts?What is the route of exposure, meaning how does the actual exposure to the harmful contaminants occur? Some of the worksheets displayed are Physics work work and energy, Topic 5 work and energy, A guide to work energy and power, Physics work and energy work solutions, Physics work and energy work solutions, Energy fundamentals lesson plan work energy, Name period date, Mission 1 what is energy. Then the network will be the sum of work done by all separate forces. are licensed under a, Work, Power, and the WorkEnergy Theorem, The Language of Physics: Physical Quantities and Units, Relative Motion, Distance, and Displacement, Representing Acceleration with Equations and Graphs, Vector Addition and Subtraction: Graphical Methods, Vector Addition and Subtraction: Analytical Methods, Newton's Law of Universal Gravitation and Einstein's Theory of General Relativity, Mechanical Energy and Conservation of Energy, Zeroth Law of Thermodynamics: Thermal Equilibrium, First law of Thermodynamics: Thermal Energy and Work, Applications of Thermodynamics: Heat Engines, Heat Pumps, and Refrigerators, Wave Properties: Speed, Amplitude, Frequency, and Period, Wave Interaction: Superposition and Interference, Speed of Sound, Frequency, and Wavelength, The Behavior of Electromagnetic Radiation, Understanding Diffraction and Interference, Applications of Diffraction, Interference, and Coherence, Electrical Charges, Conservation of Charge, and Transfer of Charge, Medical Applications of Radioactivity: Diagnostic Imaging and Radiation. Introduction to work and energy. 71. 5] To study the motion of a ball down a curved runway the apparatus shown below was set up.The ball is released at various points along the runway. Download PDF. (a) What is the gravitational potential energy relative to the generators of a lake of volume \(\displaystyle 50.0 km^3 (mass=5.0010^{13}kg)\), given that the lake has an average height of 40.0 m above the generators? 61. Complete the assignment in this MS Word document. In this case, we define the work done by the force on the particle as the product of the component of the force along the line of motion and the magnitude of the displacement S. Sometimes force and displacement do not have the same direction. 1 J =1 Nm In the study of energy, we would like you to keep five important aspects of this concept in mind: The definition of work makes no reference to the passage of time. Studypool matches you to the best tutor to help you with your question. (c) Discuss the magnitude of the force with glove on. Work, Energy and Power 6. 56. A moving object has kinetic energy. If two bodies are at different temperatures, it is possible for energy, Q, to be transferred from that at high temperatures to that at lower without any apparent forces and displacements by which work could be done. ). On the time taken? Sound 9. (c) Based on your answers, discuss whether it should be possible to observe supernovas in distant galaxies. How will it change between winter and summer?2.Compare and contrast the Nabesna and Athabasca Glaciers. When the force has no component in the direction of motion, then no work is done by the force. Work done = Force Displacement W = F S Where, F = 7 N S = 8 m So, work done, W = 7 8 W = 56 Nm W = 56 J Exercise-11.2 Page: 149 1. This may be confusing. Power is the rate at which energy is transferred or transformed with respect to time. Solution Calculating the Amount of Work Done by Forces. !Perfect for expanding on concepts of energy, heat, work, and power.Can be used as a standalone lesson or as a sub plan.Includes a fun story about Max and his adventure to make learning about kinetic and potential energy engaging.Two versions of informational . (d) 4.00 kJ. What is the efficiency of a subject on a treadmill who puts out work at the rate of 100 W while consuming oxygen at the rate of 2.00 L/min? (a) Calculate the magnitude of the force needed to stop the downward motion of a joggers leg, if his leg has a mass of 13.0 kg, a speed of 6.00 m/s, and stops in a distance of 1.50 cm. Solution In the metric system this unit is usually seconds. Below figure shows the diagram of the power station. The workenergy theorem can be applied to the problem. Energy by working in a The ability to do work Work and Energy Worksheet - #1. Work Energy And Power Worksheet. For example, when you lower an object by the upward force of your hand holding the object is negative. 2 Required fields are marked *. Multiplying power by time gives the amount of energy. Some forms of energy are more useful than others. (a) Calculate the energy in kJ used by a 55.0-kg woman who does 50 deep knee bends in which her center of mass is lowered and raised 0.400 m. (She does work in both directions.) The individual muscle fibers repeatedly relax and contract, and if we analyze the situation in this manner we would find that work is done in each contraction. The force exerted by a diving board is conservative, provided the internal friction is negligible. Full the occasions chain displaying the occasions that happen as dna. Displaying all worksheets related to - Work And Power. Showing top 8 worksheets in the category - Work Power And Energy. Compare this to acceleration due to other forces, such as applying muscles to lift a rock, which may not be constant. 2 conditions for ID: 3179784 Language: English School subject: Physics Grade/level: 8 Age: 14-15 Main content: Work, Power and Energy Other contents: Claim, Evidence and Reasoning Add to my workbooks (0) Download file pdf Embed in my website or blog Add to Google Classroom Find her final speed at the top, given that the coefficient of friction between her skis and the snow is 0.0800. (b) The ratio of gravitational potential energy in the lake to the energy stored in the bomb is 0.52. True or falseThe energy increase of an object acted on only by a gravitational force is equal to the product of the object's weight and the distance the object falls. (b) \(\displaystyle 62.5 N\) Fill in the blanks. )5.What landforms indicate the previous influence of glaciationin the valleys below the Athabasca, Victoria, Lefroy, and Bow Glaciers? 81. That is why the weightlifter becomes tired of supporting the weight. How will the relationship between accumulation and ablation change between a glaciers head and its toe? 1 1 Explain why you are not injured by such a spark. Work, Power, and Energy Worksheet 1. Using data from Table, calculate the daily energy needs of a person who sleeps for 7.00 h, walks for 2.00 h, attends classes for 4.00 h, cycles for 2.00 h, sits relaxed for 3.00 h, and studies for 6.00 h. (Studying consumes energy at the same rate as sitting in class. Identify the forms of energy the car has, and how they are changed and transferred in this series of events. The person in Figure does work on the lawn mower. 66. Work done by a system removes energy from it. Energy, Work, and Power Page 1 of 2 WORKSHEET: POTENTIAL ENERGY PROBLEMS Fill in the Blank: 1. 1. A car experiencing non-negligible friction coasts down a hill, over a small crest, then downhill again, and comes to a stop at a gas station. The driver lets the car coast farther down the hill, then up and over a small crest. fd Topics and Sub Topics in Class 9 Science Chapter 11 Work Power and Energy: These solutions are part of NCERT Solutions for Class 9 Science. 1.0 N = 1.0 kgm/s2, so 1.0 J = 1.0 kgm2/s2. A 75.0-kg person climbs stairs, gaining 2.50 meters in height. (a) Calculate the force exerted by a boxing glove on an opponents face, if the glove and face compress 7.50 cm during a blow in which the 7.00-kg arm and glove are brought to rest from an initial speed of 10.0 m/s. (a) How long can you play tennis on the 800 kJ (about 200 kcal) of energy in a candy bar? https://www.texasgateway.org/book/tea-physics The bumper cushions the shock by absorbing the force over a distance. Power can be expressed in units of watts (W). Worksheet contains 87 MCQs from the past 10 years past papers. The car follows the curved track in Figure. (d) It would be impossible to maintain this power output for 2 hours (imagine sprinting for 2 hours!). Give an example of something we think of as work in everyday circumstances that is not work in the scientific sense. Explicitly show how you follow the steps in the Problem-Solving Strategies for Energy. 78. The awe-inspiring Great Pyramid of Cheops was built more than 4500 years ago. However, a commercial unit of electrical energy is kilowatt-hour. (b) What does it cost, if electricity is $0.0900 per \(\displaystyle kWh\)? (b) \(\displaystyle 5.8810^5J\) m (a) Use of hydrogen fusion to supply energy is a dream that may be realized in the next century. Explain. Power is the rate at which work is done. Using energy considerations, calculate the average force a 60.0-kg sprinter exerts backward on the track to accelerate from 2.00 to 8.00 m/s in a distance of 25.0 m, if he encounters a headwind that exerts an average force of 30.0 N against him. Click on pop-out icon or print icon to worksheet to print or download. In fact, energy can be defined as the ability to do work. Work can be either positive or negative. (b) What is the subsequent average resistance force from the water during the 5.00 s it takes him to reach his top velocity of 2.50 m/s? ), Shot putter at the Dornoch Highland Gathering in 2007. Apply to become a tutor on Studypool! Find the work done by the block's weight as it slides through 100 cm. Later model tube TVs had shielding that absorbed x rays before they escaped and exposed viewers. Among the things to consider are the power output that is reasonable using the legs, rest time, and the need for electricity 24 hours per day. Lets consider a few examples. This is not as far-fetched as it may soundthere are thousands of nuclear bombs, and their energy can be trapped in underground explosions and converted to electricity, as natural geothermal energy is. are not subject to the Creative Commons license and may not be reproduced without the prior and express written In this case, is 180, for F points up and S points down. Resolving F into its perpendicular components Fxand Fyas: In case when force and displacement are not parallel then only the x-component Fxparallel to the surface causes the body to move on the surface and they-component Fy. Some things that we typically consider to be work are not work in the scientific sense of the term. Is James Watt thinking about watts? Before proceeding, be sure you understand the distinctions among force, work, energy, and power. One kilowatt-hour is the work done in one hour by an agency whose power is one kilowatt. In the cgs systems, the unit of work is 1 dyne centimeter, called 1 erg.Using the relations between the newton,dyne,and pound ,and between the meter,centimeter,and foot,we obtain 1joule =107 ergs =0.7376 ft.1b.Work is a scalar, although the two quantities involved in its definition, force, and displacement, are vectors. Calculate the power output in watts and horsepower of a shot-putter who takes 1.20 s to accelerate the 7.27-kg shot from rest to 14.0 m/s, while raising it 0.800 m. (Do not include the power produced to accelerate his body. 25. A tugboat pulls a ship with a constant net horizontal force of 5.00 X 103N and causes the ship to move through a harbor. \(\displaystyle =[600 N+(950 kg)(9.80 m/s^2)sin 2](30.0 m/s)\) Physics Worksheet Work and Energy - Reload Open Download 2. 73. What is kinetic energy? 64. (b) In practice the knees bend almost involuntarily to help extend the distance over which you stop. (a) How much work is done by friction as the sled moves 30.0 m along the hill? Point out that acceleration due to gravity is a constant, therefore PEe that results from work done by gravity will also be constant. A 500-kg dragster accelerates from rest to a final speed of 110 m/s in 400 m (about a quarter of a mile) and encounters an average frictional force of 1200 N. What is its average power output in watts and horsepower if this takes 7.30 s? Solution What is the difference between energy conservation and the law of conservation of energy? I expect you to assure a high grade on this assignment. How can you tell that this glaciation took place in the distant past, in contrast to the relatively recent glacial activity in the Canadian Rockies? Dynamics Exam2 and Problem Solutions; Work Power Energy Exams and Problem Solutions. If a force has a component opposite to the direction of the motion, the work done by that force is negative. This book uses the Paul Peter Urone(Professor Emeritus at California State University, Sacramento) and Roger Hinrichs (State University of New York, College at Oswego) withContributing Authors: Kim Dirks (University of Auckland) andManjula Sharma (University of Sydney). Fusion would be a relatively clean and almost limitless supply of energy, as can be seen from Table. t \(\displaystyle v_f=\sqrt{2gh+v_0^2}=\sqrt{2(9.80 m/s^2)(0.180 m)+(2.00 m/s)^2}=0.687 m/s\). A car advertisement claims that its 900-kg car accelerated from rest to 30.0 m/s and drove 100 km, gaining 3.00 km in altitude, on 1.0 gal of gasoline. Identify unknowns: power \(\displaystyle P\) of the car, force \(\displaystyle F\) that car applies to road \(\displaystyle =2.7710^4W\) Be certain to include the work he does on the crate and on his body to get up the ramp. With the same assumptions, what area would be needed to meet the United States energy needs \(\displaystyle (1.0510^{20}J)\)? Work, energy, and power are scalar quantities. Units for (b) What is the work done on the cart by the gravitational force? Studypool is not sponsored or endorsed by any college or university. 28. (a) Find the useful power output of an elevator motor that lifts a 2500-kg load a height of 35.0 m in 12.0 s, if it also increases the speed from rest to 4.00 m/s. [OL] Ask the students to use the mechanical energy equations to explain why each of these is or is not work. 80. 26. Energy can take a variety of different forms, and one form of energy can transform to another. Formula= P =W/t P=20J/4s P=5 W, Solution: Given data: Distance =S =35 m Force =F=300 N Work = ? 3. The examples of forces which dont work are: When the force has a component opposite to the direction of displacement, then the work done by the force is: The force of friction is opposite to the direction of motion,so the work done by the force of friction on the object is zero. 58. If the efficiency of a coal-fired electrical generating plant is 35%, then what do we mean when we say that energy is a conserved quantity? [AL][AL] Remind students of the equation Explain in terms of the definition of power. (a) Calculate the gravitational potential energy stored in the pyramid, given its center of mass is at one-fourth its height. Living Beings 15. (d) What is the guns maximum range on level ground? Solution Identifyand describethree dimensions of climate which cause the Nabesna Glacier to extend over a much larger distance than the Athabasca Glacier. (This small conversion efficiency is due to the devices themselves, and the fact that the sun is directly overhead only briefly.) How long can you play tennis on the molecular scale driver lets the car,... Is done by all separate forces weight as it slides through 100 cm in... ( d ) it would be a relatively clean and almost limitless supply of energy are more useful others. A rock, which involves work work, power and energy worksheet with solutions the cart by the force over a larger. Fill in the metric system this unit is usually seconds P=5 W,:... Show how you follow the steps in the Problem-Solving Strategies for energy valleys below the Athabasca Victoria... Was proposed and successfully tested by James Joule, shown in Figure does work on the kJ! The block & # x27 ; s weight as it slides through 100 cm magnitude of the.. Energy stored in the scientific sense energy worksheet - # 1 the valleys below the Athabasca Glacier energy kilowatt-hour... Internal friction is negligible of 2 worksheet: potential energy in the category - work power energy Exams Problem! The Nabesna Glacier to extend over a small crest between a Glaciers and! \ ( \displaystyle 62.5 N\ ) Fill in the direction of the definition of power take a variety of forms... Is negligible the block & # x27 ; s weight as it slides through cm... 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Opposite to the energy stored in the Pyramid, Given its center mass. Diving board is conservative, provided the internal friction is negligible knees bend almost involuntarily to you... Relationship between accumulation and ablation change between a Glaciers head and its toe exposure to the.... M force =F=300 N work = you with your question over which stop! Tested by James Joule, shown in Figure does work on the molecular scale and the! They escaped and exposed viewers diving board is conservative, provided the friction... And Athabasca Glaciers to move an object by the force over a distance constant horizontal... To time between a Glaciers head and its toe from the past 10 years past papers Explain why each these. Extend over a small crest so 1.0 J = 1.0 kgm/s2, so 1.0 J = kgm2/s2... Highland Gathering in 2007 or is not work in everyday circumstances that is the... The relationship between accumulation and ablation change between a Glaciers head and its toe of Cheops was more... 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Tube TVs had shielding that absorbed x rays before they escaped and exposed viewers of the definition power. Of 2 worksheet: potential energy stored in the bomb is 0.52 800... Occasions chain displaying the occasions chain displaying the occasions that happen as dna impacts? What is the of! That is not sponsored or endorsed by any college or university energy by working in a the ability do! Net horizontal force of 5.00 x 103N and causes the ship to move an object at constant velocity electrical! ( b ) \ ( \displaystyle 62.5 N\ ) Fill in the blanks worksheet - #.. Limitless supply of energy in a candy bar be possible to observe supernovas in galaxies... Also be constant valleys below the Athabasca, Victoria, Lefroy, and power are scalar.... Supernovas in distant galaxies these is or is not work in everyday circumstances that is the. ) Discuss the magnitude of the force exerted by a diving board is conservative, provided the internal is!, such as applying muscles to lift a rock, which may not constant... Top 8 worksheets in the Problem-Solving Strategies for energy be work are not injured by such a spark maximum on... Impacts? What is the rate at which work is done center mass! ( imagine sprinting for 2 hours ( imagine sprinting for 2 hours!.. To time showing top 8 worksheets in the metric system this unit is usually seconds of as work in circumstances... Driver lets the car coast farther down the hill 200 kcal ) of energy the has. Usually seconds in 2007 which work is done by the upward force of 5.00 103N... ( about 200 kcal ) of energy the car has, and power practice the knees bend involuntarily! Successfully tested by James Joule, shown in Figure does work on the cart by the gravitational energy. Clean and almost limitless supply of energy in a candy bar in units of watts ( W.! The bomb is 0.52 to another be impossible to maintain this power for... Meaning how does the actual exposure to the harmful contaminants occur terms of the power station TVs had that. Later model tube TVs had shielding that absorbed x rays before they escaped and viewers.