Class 9 Practice Level 2 – Work and Energy – Set 1 Leave a Comment / By Gulam Hamza / July 10, 2024 Class 9 Practice Level 2 - Work and Energy - Set 1 Total questions: 25 1. A force of 50 N is applied to push a box 4 meters across a floor. If the force is applied at an angle of 30 degrees to the horizontal, what is the work done by the force? 100 J 150 J 173.2 J 200 J None 2. A car of mass 1000 kg is moving with a speed of 20 m/s. What is its kinetic energy? 100,000 J 200,000 J 300,000 J 400,000 J None 3. If a pump raises 100 liters of water per minute to a height of 20 meters, what is the power of the pump? $ \displaystyle \left( {Take\text{ }g=10\,m/s2g\text{ },1\text{ }liter\text{ }of\text{ }water\text{ }=\text{ }1\text{ }kg} \right)$ 333 W 500 W 667 W 1000 W None 4. An object is lifted vertically 5 meters by a force of 100 N. What is the work done against gravity? 200 J 300 J 400 J 500 J None 5. A pendulum bob of mass 0.5 kg is raised to a height of 0.2 meters. What is its potential energy at this height? $ \displaystyle \left( {Take\text{ }g=10\,m/{{s}^{2}}} \right)$ 1 J 2 J 3 J 4 J None 6. A machine does 4000 joules of work in 20 seconds. What is its power output? 100 W 150 W 200 W 250 W None 7. A boy pulls a cart with a force of 50 N over a distance of 10 meters in 5 seconds. What is the power exerted by the boy? 50 W 100 W 150 W 200 W None 8. A ball of mass 0.2 kg is moving with a velocity of 5 m/s. What is its kinetic energy? 1 J 2 J 2.5 J 3 J None 9. If a motor does 1500 J of work in 5 seconds, what is its power output? 200 W 250 W 300 W 350 W None 10. A crane lifts a load of 500 kg to a height of 10 meters. How much work is done? $ \displaystyle \left( {Take\text{ }g=10\,m/{{s}^{2}}} \right)$ 50,000 J 5000 J 25,000 J 1000 J None 11. A spring with a spring constant of 200 N/m is compressed by 0.1 meters. What is the potential energy stored in the spring? 1 J 2 J 0.5 J 10 J None 12. A person does 300 J of work by lifting a box in 6 seconds. What is the power developed by the person? 40 W 50 W 60 W 70 W None 13. A force of 30 N is applied to move a box 7 meters. The force is applied at an angle of 45 degrees to the direction of motion. What is the work done? 70 J 105 J 148 J 210 J None 14. A 2 kg object is dropped from a height of 10 meters. What is its kinetic energy just before it hits the ground? $ \displaystyle \left( {Take\text{ }g=10\,m/{{s}^{2}}} \right)$ 100 J 150 J 200 J 250 J None 15. An electric heater uses 1500 J of energy in 10 seconds. What is its power rating? 100 W 150 W 1500 W 15 W None 16. A person pulls a sled with a force of 40 N at an angle of 60 degrees to the horizontal. If the sled is pulled a distance of 5 meters, what is the work done? 100 J 200 J 1000 J 300 J None 17. A 5 kg object is moving with a velocity of 10 m/s. What is its kinetic energy? 100 J 200 J 250 J 300 J None 18. A person does 600 J of work in 3 minutes. What is the power developed by the person in watts? 2 W 3.33 W 5 W 10 W None 19. An electric motor lifts a 10 kg object to a height of 8 meters in 4 seconds. What is the power output of the motor? $ \displaystyle \left( {Take\text{ }g=10\,m/{{s}^{2}}} \right)$ 100 W 200 W 300 W 400 W None 20. A stone of mass 0.5 kg is thrown vertically upward with an initial velocity of 15 m/s. What is its kinetic energy at the highest point? 0 J 37.5 J 56.25 J 112.5 J None 21. An electric pump does 9000 J of work in pumping water in 60 seconds. What is the power of the pump? 100 W 150 W 200 W 250 W None 22. A person pushes a 20 kg box with a force of 60 N over a distance of 3 meters in 15 seconds. What is the work done on the box? 60 J 120 J 180 J 240 J None 23. A 1 kg ball is thrown vertically upwards with a speed of 10 m/s. What is the maximum height it reaches.$ \displaystyle \left( {Take\text{ }g=10\,m/{{s}^{2}}} \right)$ 2 m 3 m 4 m 5 m None 24. A person weighing 600 N climbs a staircase of 10 meters height in 20 seconds. What is the power developed by the person? 200 W 300 W 400 W 500 W None 25. If a machine does 3000 J of work in moving an object 10 meters, what is the force exerted by the machine? 100 N 200 N 300 N 400 N None 1 out of 25 Time's up