Work and Energy...

If water is flowing in a pipe at a height 4m from the ground then its potential
energy per unit volume is (Reference is taken at ground, $$  g=10 \mathrm{m} / \mathrm{s}^{2} )  $$

A body is moved along a straight line by a machine delivering constant power. The distance moved by the body in time $$t$$ is proportional to

If a body is released from a certain height, during its fall.

When the force and the displacement are in the opposite directions, the work done by the force is ..........

A machine delivering constant power moves a body along straight line starting from rest. The distance moved by the body in time $$t$$ is proportional to

A ball of mass 2 kg hits a floor with a speed of 4 m/s at an angle of $$ 60 ^o $$ with the normal.
If (e=1/2); then the change in the kinetic energy of the ball is

From an automatic gun a man fires 360 bullets per minute with a speed of 360 km/hr. If each bullet weighs 20g, the power of the gun is

A body of mass 200 g moving on a test has final K.E. of 50 J after travelling a distance of 10 cm. Assuming 90% loss of energy due to friction. The initial speed of the body is 

Potential energy v/s displacement curve for one dimensional conservative field is shown. Force at A and B is respectively -

A block of mass $$20 kg$$ is being brought down by a chain. If block acquires a speed of $$2 m/s$$ in dropping down $$2 m$$. Find work done by the chain during the process. ($$g= 10m/s^{2}$$ )