28/03/2020Energy, Work and Power(Senior Class Physics Study by Topics) 0Comments by Gate Academy Welcome to your Energy, Work and Power(Senior Class Physics Study by Topics) NAME EMAIL PHONE NUMBER 1. A ball is projected into the air with 100 J of kinetic energy which is transformed to gravitational potential energy at the top of its trajectory. When it returns to its original level after encountering air resistance, its kinetic energy is _____. More than 100 J. Less than 100 J. 100 J. Not enough information given.2. When a body slides against a rough horizontal surface, the work done by friction is _____ Positive Zero Constant Negative3. When a gas filled in a cylinder fitted with a movable piston is allowed to expand, the work done by the gas is positive. False True4. When a body is lifted, the work done by the gravitational force is positive. True False5. When a light body collides with a massive body at rest _____ No reaction happens The light body rebounds after the collision The massive body rebounds after the collision The light body Remains at rest6. When an object is lifted 10 meters, it gains a certain amount of potential energy. If the same object is lifted 20 meters, its potential energy is ______. Twice as much. Less. The same Four times as much7. Which one of the following is not the unit of energy? Newton meter Joule Kilowatt hour Kilowatt8. A man of mass 50 kg jumps to a height of 1 m. His potential energy at the highest point is (g = 10 m/s2): 500 J 50 J 5 J 5000 J9. If you push on a wall with a force of 30 N, then ______________. You are pulled towards the wall. The wall moves back 3 cm. The wall pushes on you with a force of 30 N. The wall cannot be forced.10. The type of energy possessed by a simple pendulum, when it is at the mean position is: Kinetic + Potential energy Sound energy Kinetic energy Potential energy11. Which of the following is not a unit for power? Horsepower Joule – second Watt Newton-meter per second12. The potential energy of an object is equal to ________ The work done on the object to put the object into its current state. The force of gravity working on the object. The size of the object compared to its surface area. The velocity of the object divided by its mass.13. Two identical arrows, one with twice the kinetic energy of the other, are fired into a hay bale. The faster arrow will penetrate _____. Four times as far as the slower arrow. Twice as far as the slower arrow. The same distance as the slower arrow. More than four times as far as the slower arrow.14. For a body moving in a circular path, the work done by the centripetal force is ________ Constant Positive Zero Negative15. Collision between two carom coins is an example for ____ Elastic collision Inelastic collision Oblique collision Perfectly inelastic collision16. A moving hammer drives a nail into the wood. It has kinetic energy. True False17. When a massive body collides against a light body at rest ____ The velocity of the bodies get exchanged The massive body comes to rest The light body rebounds The light body starts moving18. A person is holding a bucket by applying a force of 10N. He moves a horizontal distance of 5m and then climbs up a vertical distance of 10m. Find the total work done by him? 100J 50J 200J 150J19. A feather and a coin dropped in a vacuum fall with equal _____. Momenta Accelerations Forces Kinetic energies20. A machine does 2500 J of work in 1 min. What is the power developed by the machine? 150 W 42 W 21 W 2500 W21. As an object goes up a hill at constant velocity, which of the following is NOT true? The object's speed is constant. The object's Kinetic Energy is constant. The object's Potential Energy is increasing. The object's Kinetic Energy is decreasing.22. A block with a mass of m crosses a rough horizontal surface at a constant speed of v. The coefficient of kinetic friction between the block and the surface isµ. How much power must be produced in order to overcome the friction force? µmg µg mg µmgv23. Two identical arrows, one with twice the speed of the other, are fired into a hay bale. The faster arrow will penetrate _____. More than four times as far as the slower arrow. Twice as far as the slower arrow. Four times as far as the slower arrow. The same distance as the slower arrow.24. When a coolie walks on a horizontal platform with a load on his head, the work done by the coolie on the load is zero. True False25. If an object has kinetic energy, then it also must have ____ Force Acceleration Impulse Speed26 out of 25Time is Up!