Class 11 Physics: Work, Energy and Power (Hard)

A body of mass 'm' is accelerated uniformly from rest to a speed 'v' in time 't'. The instantaneous power delivered to the body at any time 'T' (0 < T < t) is:

A particle moves along the X-axis from x=0 to x=5m under the influence of a force F = (7 - 2x + 3x^2) N. The work done in joules is:

A spring is stretched by 5 cm by a force of 10 N. The work done in stretching the spring by an additional 5 cm will be:

An engine pumps water continuously through a hose. Water leaves the hose with a velocity 'v' and 'm' is the mass per unit length of the water jet. What is the rate at which kinetic energy is imparted to water?

A ball is dropped from a height 'h' onto a horizontal surface. If the coefficient of restitution is 'e', the height to which it rebounds after 'n' impacts is:

When a conservative force does positive work on a body, the potential energy of the body _________.

The angle between the applied force and the displacement for maximum work done is _________ degrees.

A particle moves from point (2,3) to (4,5) in a conservative force field given by F = (3x^2 i + 4y j) N. The work done by this force is _________ J.

Explain why the work done by the centripetal force in uniform circular motion is always zero.

Consider a block of mass 'm' moving up an inclined plane with constant velocity. Discuss how the work done by friction, gravity, and the applied force are related to the change in kinetic and potential energy.