Class 9 Work and Energy Quiz set 2 1. One kilowatt is approximately equal to 2.50 hp 1.83 hp 1.30 hp 1.56 hp 2. The moon revolves around the around the earth because the earth exerts a radial force on the moon. Does the earth perform work on the moon? Yes, always cannot be decided No Yes, sometimes 3. A steam engines coverts mechanical energy into heat energy heat energy into mechanical energy heat energy into sound energy electrical energy into sound energy 4. A raised hammer possesses Gravitational P.E. sound energy K.E. only electrical energy 5. When a body is whirled in a circle, the work Zero Negative Infinite Positive 6. when the force applied and the displacement of the body are inclined at 90° with each other the work done is maximum zero infinite unity 7. kWh represents the unit for Time Power Force Energy 8. Watt sec represents the units for kWh erg Ws Js 9. A body of mass m kg is lifted by a man to a height of one meter in 30 s. Another man lifts the same mass to the same height in 60 s. The Work done by them is in the ratio 1 : 1 2 : 1 1 : 2 4 : 1 10. what is the momentum of a body of mass 100 g having K.E. of 20 J ? 2 kg m/s 1/2 kg m/s 2 g cm/s none of these 11. When the speed of a moving object is doubled, its K.E. becomes 4 times K.E. is doubled acceleration is doubled weight is doubled 12. Two bodies of equal weight are kept at height of h and 1.5h respectively. The ratio of their P.E. is 3 : 2 none of these 1 : 1 2 : 3 13. When the momentum of a body increases by 100%, its K.E. increases by 400 % 40% 100 % 20% 14. what is the momentum of a body of mass 100 g having K.E. of 20 J ? 1/2 kg m/s 2 kg m/s 2 g cm/s none of these 15. When the momentum of a body increases by 10%, its K.E. increases by 44% 20% none of these 40% Loading …
Comments