28/03/2020 Energy, 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 bullet fired from a gun can pierce a target due to its ___________AccelerationMechanical energyKinetic energyHeat energy2. Which one of the following is not the unit of energy?KilowattJouleKilowatt hourNewton meter3. 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?150J200J100J50J4. A machine gun fires 60 bullets per minute, with a velocity of 700m/s. If each bullet has a mass of 50g, find the power developed by the gun.122W1225W12250W122.5W5. 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.6. When a body slides against a rough horizontal surface, the work done by friction is _____ZeroPositiveNegativeConstant7. "Power" is defined as ________The sum of potential and kinetic energyThe energy necessary to do workThe velocity of an object squaredThe rate at which work is done8. 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?mgµmgµgµmgv9. A man of mass 50 kg jumps to a height of 1 m. His potential energy at the highest point is (g = 10 m/s^{2}):5000 J50 J5 J500 J10. When a massive body collides against a light body at rest ____The massive body comes to restThe light body starts movingThe light body reboundsThe velocity of the bodies get exchanged11. Mud thrown on a wall and sticking to it is an example for _____Elastic collisionPerfectly inelastic collisionInelastic collisionSuper elastic collision12. Collision between two carom coins is an example for ____Oblique collisionInelastic collisionPerfectly inelastic collisionElastic collision13. If a force acts perpendicular to the direction of motion of a body, what is the amount of work done?InfinityZeroSinθConstant14. A machine does 2500 J of work in 1 min. What is the power developed by the machine?21 W150 W42 W2500 W15. A gardener pushes a lawn roller through a distance of 20m. If he applies a force of 20kg weight in a direction inclined at 60° to the ground, find the work done by him. (g=9.8m/s^{2})2514J400J250J1960J16. The momentum of a bullet of mass 20 g fired from a gun is 10 kg.m/s. The kinetic energy of this bullet in kJ will be:250.252.5517. If a mass is at rest, what must be applied to cause it to move? ForceVectorsKilogramsSpeed18. A car travels with a constant speed of 15 m/s. The car’s engine produces a 4000 N pushing force in order to keep the speed constant. How much power isdeveloped by the engine?60000 W6000 W60 W600 W19. A moving hammer drives a nail into the wood. It has kinetic energy.TrueFalse20. If an object has kinetic energy, then it also must have ____SpeedAccelerationImpulseForce21. An object that has potential energy has this energy because of its ____Speed.LocationAcceleration.Momentum.22. A feather and a coin dropped in a vacuum fall with equal _____. ForcesAccelerationsMomentaKinetic energies23. An object with mass "m" kilograms is suspended "h" meters above the ground by a string. If the string is cut, what will the velocity of the object be at the instant it hits the ground?Two times ghm squaredH-2gmThe square root of 2ghOne-half the mass squared24. As an object goes up a hill at constant velocity, which of the following is NOT true?The object's Potential Energy is increasing.The object's speed is constant.The object's Kinetic Energy is constant.The object's Kinetic Energy is decreasing.25. When a light body collides with a massive body at rest _____The massive body rebounds after the collisionThe light body Remains at restNo reaction happensThe light body rebounds after the collision26 out of 25Time is Up! Time's up