If the momentum of a body is doubled, the kinetic energy becomes _______ times.

Define energy. What is its S.l. unit? Is energy a scalar or a vector quantity?

What are the various forms of energy? Give some examples of each.

Define kinetic energy. Derive an expression for it.

A boy of mass$18 \mathrm{kg}$  is running with a speed of $12 \mathrm{km}/\mathrm{hr}$. Find the kinetic energy possessed by the boy.

Given that the kinetic energy of an object is $100 \mathrm{J}$. If the mass of an object is $2 \mathrm{kg}$ then find its speed.

A stationary football is kicked by a player such that it attains a speed of $3 \mathrm{m}/\mathrm{s}$ just after the kick. Find the work done by the player on the ball if the mass of the ball is $100 \mathrm{g}$.

Find the work done in increasing the speed of a car from $18 \mathrm{km} {\mathrm{h}}^{-1}$ to $36 \mathrm{km} {\mathrm{h}}^{-1}$. Given, the mass of the car is $1000 \mathrm{kg}$.

Does the potential energy of spring increase when it is in the state of extension, and decrease when it is in the state of compression?