Slide 1 / 44 Slide 2 / 44 8th Grade Energy of Objects in Motion Study Guide 2015-08-25 www.njctl.org Slide 3 / 44 1 Energy is defined as the ability to do what? Slide 3 () / 44 1 Energy is defined as the ability to do what? move move float float work none of the above work none of the above Slide 4 / 44 2 In order for work to be done on an object, what two things are needed? Slide 4 () / 44 2 In order for work to be done on an object, what two things are needed? force and time force and time force and displacement force and displacement mass and time mass and displacement mass and time mass and displacement
Slide 5 / 44 3 Which of the following types of energy looks at objects at the atomic level? mechanical energy non-mechanical energy total energy renewable energy Slide 5 () / 44 3 Which of the following types of energy looks at objects at the atomic level? mechanical energy non-mechanical energy total energy renewable energy Slide 6 / 44 4 Mechanical energy is the energy associate with what? motion and mass motion and position mass and position position and time Slide 6 () / 44 4 Mechanical energy is the energy associate with what? motion and mass motion and position mass and position position and time Slide 7 / 44 5 Which types of energy make up mechanical energy? kinetic potential kinetic and potential None of the above Slide 7 () / 44 5 Which types of energy make up mechanical energy? kinetic potential kinetic and potential None of the above
Slide 8 / 44 6 Which of the following is a form of non-mechanical energy? kinetic potential solar none of the above Slide 8 () / 44 6 Which of the following is a form of non-mechanical energy? kinetic potential solar none of the above Slide 9 / 44 7 Potential energy is also called what? energy of ability stored energy hopeful energy none of the above Slide 9 () / 44 7 Potential energy is also called what? energy of ability stored energy hopeful energy none of the above Slide 10 / 44 8 Two objects of different masses are moving with the same speed. Which one has more kinetic energy? Slide 10 () / 44 8 Two objects of different masses are moving with the same speed. Which one has more kinetic energy? the heavier one the heavier one the lighter one the lighter one They both have the same kinetic energy Neither one has kinetic energy They both have the same kinetic energy Neither one has kinetic energy
Slide 11 / 44 Slide 11 () / 44 9 baseball is thrown to a batter. Which pitcher throws the ball with more kinetic energy? 9 baseball is thrown to a batter. Which pitcher throws the ball with more kinetic energy? a little league pitcher a little league pitcher a middle school pitcher a middle school pitcher a major league pitcher they all have the same kinetic energy a major league pitcher they all have the same kinetic energy Slide 12 / 44 Slide 12 () / 44 10 When is the only time that an object does not have kinetic energy? 10 When is the only time that an object does not have kinetic energy? when it is on Earth's Surface when it is on Earth's Surface when it is above Earth's surface when it is above Earth's surface when it is not moving an object always has kinetic energy when it is not moving an object always has kinetic energy Slide 13 / 44 Slide 13 () / 44 11 Two identical objects sit on top of roofs at different heights above the Earth's surface. Which has more gravitational potential energy? the one on the shorter roof the one on the taller roof they both have the same gravitational potential energy neither one has gravitational potential energy 11 Two identical objects sit on top of roofs at different heights above the Earth's surface. Which has more gravitational potential energy? the one on the shorter roof the one on the taller roof they both have the same gravitational potential energy neither one has gravitational potential energy
Slide 14 / 44 12 Two objects sit on top of the roof of a building. The first object is a bowling ball and the second is a tennis ball. Which one has more gravitational potential energy? the bowling ball the tennis ball they have the same gravitational potential energy They both have zero gravitational potential energy Slide 14 () / 44 12 Two objects sit on top of the roof of a building. The first object is a bowling ball and the second is a tennis ball. Which one has more gravitational potential energy? the bowling ball the tennis ball they have the same gravitational potential energy They both have zero gravitational [This object is a pull potential tab] energy Slide 15 / 44 13 n object is lifted to a height of 10m above a planet's surface. On which planet would the object have more gravitational potential energy? on Earth where gravity is 9.8m/s 2 on Jupiter where gravity is 24.5m/s 2 on Mars where gravity is 3.7m/s 2 the gravitational potential energy would be the same on all planets Slide 15 () / 44 13 n object is lifted to a height of 10m above a planet's surface. On which planet would the object have more gravitational potential energy? on Earth where gravity is 9.8m/s 2 on Jupiter where gravity is 24.5m/s 2 on Mars where gravity is 3.7m/s 2 the gravitational potential energy would be the same on all planets Slide 16 / 44 14 What is the "tightness" of a spring called? relaxed length spring constant tension none of the above Slide 16 () / 44 14 What is the "tightness" of a spring called? relaxed length spring constant tension none of the above
Slide 17 / 44 15 In order for a spring to have stored energy, the spring must be. Slide 17 () / 44 15 In order for a spring to have stored energy, the spring must be. stretched stretched compressed compressed stretched or compressed none of the above stretched or compressed none of the above Slide 18 / 44 16 Two identical rubber bands are stretched. Rubber band is stretched 1m. Rubber band is stretched 2m. How many times larger is the stored energy in rubber band compared to rubber band? Slide 18 () / 44 16 Two identical rubber bands are stretched. Rubber band is stretched 1m. Rubber band is stretched 2m. How many times larger is the stored energy in rubber band compared to rubber band? equal 2 times larger 4 times larger none of the above equal 2 times larger 4 times larger none of the above Slide 19 / 44 17 rubber band and a trampoline spring are both stretched by 0.25 m. Which has more elastic potential energy present? the rubber band the trampoline spring neither one has elastic potential energy present they both have elastic potential energy present Slide 19 () / 44 17 rubber band and a trampoline spring are both stretched by 0.25 m. Which has more elastic potential energy present? the rubber band the trampoline spring neither one has elastic potential energy present they both have elastic potential energy present
Slide 20 / 44 18 Which of the following is allowed according to the Law of onservation of Energy? Energy is lost Energy is gained Energy is transferred None of the above Slide 20 () / 44 18 Which of the following is allowed according to the Law of onservation of Energy? Energy is lost Energy is gained Energy is transferred None of the above Slide 21 / 44 19 t which point on the diagram shown does the roller coaster car have the largest gravitational potential energy? Slide 21 () / 44 19 t which point on the diagram shown does the roller coaster car have the largest gravitational potential energy? Slide 22 / 44 20 t which point in the diagram shown does the object only have kinetic energy? Slide 22 () / 44 20 t which point in the diagram shown does the object only have kinetic energy?
Slide 23 / 44 21 t which point does the object have elastic potential energy? Slide 23 () / 44 21 t which point does the object have elastic potential energy? Slide 24 / 44 22 t which point in the diagram is the object traveling the fastest? Slide 24 () / 44 22 t which point in the diagram is the object traveling the fastest? Slide 25 / 44 23 t what point in the diagram does the object have both kinetic and gravitational potential energy? Slide 25 () / 44 23 t what point in the diagram does the object have both kinetic and gravitational potential energy?
Slide 26 / 44 24 What must be true in the diagram shown in order for all of the energy of the system present at point to be in the form of elastic potential energy? Slide 26 () / 44 24 What must be true in the diagram shown in order for all of the energy of the system present at point to be in the form of elastic potential energy? the object must be moving the object must be stopped it is impossible for all of the energy to be elastic potential energy the object must be moving the object must be stopped it is impossible for all of the energy to be elastic potential energy Slide 27 / 44 25 Which of the following types of energy resources is considered a renewable energy resource? Slide 27 () / 44 25 Which of the following types of energy resources is considered a renewable energy resource? Wind Wind Water Water Solar ll of the above Solar ll of the above Slide 28 / 44 26 Wind turbines convert what type of energy into electrical energy? Potential Kinetic Solar None of the above Slide 28 () / 44 26 Wind turbines convert what type of energy into electrical energy? Potential Kinetic Solar None of the above
Slide 29 / 44 27 Which of the following forms of energy resources does not use a turbine in converting mechanical energy into electrical energy? Slide 29 () / 44 27 Which of the following forms of energy resources does not use a turbine in converting mechanical energy into electrical energy? Solar Solar Wind Wind Hydroelectric Fossil Fuels Hydroelectric Fossil Fuels Slide 30 / 44 28 Which of the following types of energy resources emits carbon dioxide when consumed to produce electrical energy? Slide 30 () / 44 28 Which of the following types of energy resources emits carbon dioxide when consumed to produce electrical energy? oal oal Oil Oil Natural Gas ll of the above Free Response: Natural Gas ll of the above Free Response: Slide 31 / 44 Slide 31 () / 44 29 What is the kinetic energy of a 2 kg object that is moving with a speed of 5 m/s? 29 What is the kinetic energy of a 2 kg object that is moving with a speed of 5 m/s? 25 J
Slide 32 / 44 30 What is the kinetic energy of a 1000 kg car that is traveling with a speed of 15 m/s? Slide 32 () / 44 30 What is the kinetic energy of a 1000 kg car that is traveling with a speed of 15 m/s? 112,500 J Slide 33 / 44 31 What is the change in a 2 kg object's kinetic energy if it increases its speed from 5 m/s to 10 m/s? Slide 33 () / 44 31 What is the change in a 2 kg object's kinetic energy if it increases its speed from 5 m/s to 10 m/s? 75 J Slide 34 / 44 32 What is the gravitational potential energy of an object that has a mass of 5 kg and is at a height of 10 m above the Earth's surface? Slide 34 () / 44 32 What is the gravitational potential energy of an object that has a mass of 5 kg and is at a height of 10 m above the Earth's surface? 490 J
Slide 35 / 44 33 What is the gravitational potential energy of a 200 kg boulder that is resting on the surface of the Earth? Slide 35 () / 44 33 What is the gravitational potential energy of a 200 kg boulder that is resting on the surface of the Earth? 0 J Slide 36 / 44 34 What is the gravitational potential energy of an object that has a mass of 2 kg and a height of 10 m on Earth where gravity is 9.8 m/s 2? Slide 36 () / 44 34 What is the gravitational potential energy of an object that has a mass of 2 kg and a height of 10 m on Earth where gravity is 9.8 m/s 2? 196 J Slide 37 / 44 35 What is the change in a 2 kg object's gravitational potential energy if the object is raised from a height of 5 m to a height of 10 m? Slide 37 () / 44 35 What is the change in a 2 kg object's gravitational potential energy if the object is raised from a height of 5 m to a height of 10 m? 98 J
Slide 38 / 44 36 What types of energy does a person have if they are running up a flight of stairs? Explain your answer. Slide 38 () / 44 36 What types of energy does a person have if they are running up a flight of stairs? Explain your answer. Kinetic- because they are running Gravitational Potential Energybecause they are elevated Slide 39 / 44 37 What is the total energy of a 2 kg object that moves at 5 m/s on a 5 m tall hill? (Hint: total energy is the sum of kinetic and potential energy) Slide 39 () / 44 37 What is the total energy of a 2 kg object that moves at 5 m/s on a 5 m tall hill? (Hint: total energy is the sum of kinetic and potential energy) Total Energy = 123 J KE = 98 J GPE = 25 J Slide 40 / 44 38 n elastic band has a spring constant of 100 N/m. If it is stretched by 0.5 m, how much elastic potential energy is stored in the band? Slide 40 () / 44 38 n elastic band has a spring constant of 100 N/m. If it is stretched by 0.5 m, how much elastic potential energy is stored in the band? 12.5 J
Slide 41 / 44 39 spring with a spring constant of 75 N/m is compressed by 2 m. How much elastic potential energy is stored in the spring? Slide 41 () / 44 39 spring with a spring constant of 75 N/m is compressed by 2 m. How much elastic potential energy is stored in the spring? 150 J Slide 42 / 44 40 ased on the graph below, is positive, negative, or no work being done on the object? Explain how you know. positive negative no work Slide 42 () / 44 40 ased on the graph below, is positive, negative, or no work being done on the object? Explain how you know. positive negative no work Slide 43 / 44 41 raw on the graph below a situation where no work is done on an object. Explain your reasoning. Slide 43 () / 44 41 raw on the graph below a situation where no work is done on an object. Explain your reasoning. ny line which has a slope of zero. This means no acceleration and therefore no force applied.
Slide 44 / 44 42 t what time on the graph below does work start to be applied to the object? Explain if it is positive or negative work. Slide 44 () / 44 42 t what time on the graph below does work start to be applied to the object? Explain if it is positive or negative work. t time equal to 1 second. Negative work is done because the velocity is decreasing meaning that the force is applied in the opposite direction of the displacement.