Assessment_11_Work_Eneryy_and_Power.pptx

Assessment - work energy and power

1. Work, Energy and Power Assessment

2. 1. Which of the following is the SI unit of work?   A   C   B   D Remember

3. 1. Which of the following is the SI unit of work?   A   C   B   D Remember Explanation: The joule is the standard unit for work and energy in the International System of Units (SI).

4. 2. When a force is applied to an object, and the object moves in the direction of the force, work is done. Which of the following scenarios involves work being done?   A   C   B   D Understand

5. 2. When a force is applied to an object, and the object moves in the direction of the force, work is done. Which of the following scenarios involves work being done?   A   C   B   D Understand Explanation: Work is done when there's a force and displacement in the same direction. Lifting a box involves both.

6. 3. A force of 10 N is applied to a box, moving it a distance of 5 meters. Calculate the work done.   A   C   B   D Apply

7. 3. A force of 10 N is applied to a box, moving it a distance of 5 meters. Calculate the work done.   A   C   B   D Apply Explanation: Work = Force x Distance = 10 N x 5 m = 50 J

8. 4. A graph shows a force-displacement curve for a spring. The area under the curve represents:   A   C   B   D Analyze

9. 4. A graph shows a force-displacement curve for a spring. The area under the curve represents:   A   C   B   D Analyze Explanation: The area under a force-displacement curve is equal to the work done.

10. 5. A student claims that if the kinetic energy of an object is doubled, its velocity will also double. Is this claim correct? Explain your answer. Evaluate

11. 5. A student claims that if the kinetic energy of an object is doubled, its velocity will also double. Is this claim correct? Explain your answer. Evaluate Answer: No, the claim is incorrect. Kinetic energy is proportional to the square of the velocity ( ). If kinetic energy doubles, the velocity increases by a factor of (approximately 1.41).  

12. 5. A 60 kg person climbs a 5-meter-high staircase in 15 seconds. What is their average power output during the climb? (Assume g = 9.8 m/s²)   A   C   B   D Apply

13. Explanation: Work done (W): Power (P):  

14. 6. A 60 kg person climbs a 5-meter-high staircase in 15 seconds. What is their average power output during the climb? (Assume g = 9.8 m/s²)   A   C   B   D Apply

15. 7. A car of mass 1000 kg accelerates from rest to a speed of 20 m/s in 10 seconds. Calculate the average power developed by the car's engine during this time. Analyze   A   C   B   D

16. Explanation: Initial kinetic energy ( ): 0 (at rest) Final kinetic energy ( ): Work done Power  

17. 7. A car of mass 1000 kg accelerates from rest to a speed of 20 m/s in 10 seconds. Calculate the average power developed by the car's engine during this time. Analyze   A   C   B   D

18. 8. A pendulum is released from a height 'h' above its lowest point. At the lowest point, which of the following statements is true? Evaluate   A   C   B   D

19. 8. A pendulum is released from a height 'h' above its lowest point. At the lowest point, which of the following statements is true? Evaluate   A   C   B   D Explanation: At the lowest point of a pendulum's swing: Potential Energy: Minimum (due to lowest height) Kinetic Energy: Maximum (due to highest speed)

20. 9. A 5 kg block slides down a frictionless ramp from a height of 2 meters. What is the block's speed at the bottom of the ramp? (Assume g = 9.8 m/s²)   A   C   B   D Apply

21. Explanation: Conservation of mechanical energy: Potential energy at the top = Kinetic energy at the bottom  

22. 9. A 5 kg block slides down a frictionless ramp from a height of 2 meters. What is the block's speed at the bottom of the ramp? (Assume g = 9.8 m/s²)   A   C   B   D Apply

23. 10. A 200 W light bulb is left on for 5 hours. Calculate the energy consumed by the bulb in kilowatt-hours (kWh). Analyze   A   C   B   D

24. Explanation: Energy Energy in kWh:  

25. 10. A 200 W light bulb is left on for 5 hours. Calculate the energy consumed by the bulb in kilowatt-hours (kWh). Analyze   A   C   B   D