Work, Energy and Power

A force F acting

on an object varies with distance x as shown here. The force is in N and x in m. The work done by the force in moving the object from x = 0 to x = 6 m is

A ball of mass 2 kg and another of mass 4 kg are dropped together from a 60 feet ball building. After a fall of 30 feet each towards earth, their respective kinetic energies will be in the ratio of

A particle of mass m1 is moving with a velocity v1 and another particle of mass m2 is moving with a velocity v2. Both of them have the same momentum but their different kinetic energies are E1 and E2 respectively. If m1 > m2 then :

A mass of 0.5 kg moving with a speed of 1.5 m/s on horizontal smooth surface, collides with a nearly weightless spring of force constant k = 50 N/m. The maximum compression of the spring would be

A particle moves along a circle of radius \(\left( {{{20} \over \pi }} \right)\) m with constants tangential acceleration. If the velocity of vthe particle is 80 m/s at the end of the second revoluation after motion has begun, the tangenti...

When a long spring is stretched by 2 cm, its potential energy is U. If the spring is stretched by 10 cm, the potential energy stored in it will be

Two springs A and B having spring constant KA and KB (KA = 2KB) are stretched by applying force of equal magnitude. If energy stored in spring A is EA then energy stored in B will be

A child is sitting on a swing. Its minimum and maximum heights from the ground 0.75 m and 2 m respectively, its maximum speed will be

A particle is projected making an angle of 45o with horizontal having kinetic energy K. The kinetic energy at highest point will be

A mass of 1 kg is thrown up with a velocity of 100 m/s. After 5 seconds, it explodes into two parts. One part of mass 400 g comes down with a velocity 25 m/s. The velocity of other part is (Take g = 10 ms\(-\)2)

If \(\overrightarrow F = \left( {60\widehat i + 15\widehat j - 3\widehat k} \right)\) N and \(\overrightarrow v = \left( {2\widehat i - 4\widehat j + 5\widehat k} \right)\) m/s, then instantaneous power is