Table of Contents
WORK AND ENERGY
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21.A body is falling from a height h. After it has fallen a height h/2, it will possess:
(A).Only potential energy
(B).Only kinetic energy
(C).Half potential and half kinetic energy
(D).More kinetic and less potential energy
Ans. C
22.Can any object have mechanical energy even if its momentum is zero? Explain.
24.The power of a motor pump is 2kW. How much water per minute the pump can raise to a height of 10m? (Given g = 10ms-2)
26.A girl having mass of 35kg sits on a trolley of mass 5kg. The trolley is given an initial velocity of 4ms-1 by applying a force. The trolley comes to rest after traversing a distance of 16m.
(a) How much work is done on the trolley?
(b) How much work is done by the girl?
(a) How much work is done by the men in lifting the box?
(b) How much work do they do in just holding it?
(c) Why do they get tired while holding it? (g = 10ms-2)
ALSO VISIT : NOTES ON WHY DO WE FALL ILL
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