Work and Energy...

The power exerted on the body at $$2\ s$$ is:

A man of mass 20 kg is running in a straight line with velocity 10 m/s. What is value of his kinetic energy?

Two bodies traveling with velocity $$20ms^{-1}$$ and $$40ms^{-1}$$ have same K.E. If the mass of the body having velocity $$40ms^{-1}$$ is 8 kg the mass of other body is 

Two men $$A$$ and $$B$$ each weighing $$80\ kg$$, run up the same stair case. While $$A$$ does it in $$20\ s, B$$ does it in $$15\ s$$. The ratio of the powers developed by $$A$$ and $$B$$ is

How much height must an object of mass $$5kg$$ be lifted to have potential energy $$5000J$$ ?$$[g=10 m/s^2]$$

A car is accelerated on a levelled road and attains a speed of $$5$$ times its initial speed. In this process , the kinetic energy of the car:

A stone is thrown upwards as shown in the diagram. When it reaches $$P,$$ which of the following has the greatest value for the stone?

No work is done when:

Potential energy of a person is minimum when:

When a stone of mass 'm' falls through a vertical height 'd', the decrease in the gravitational energy is: