How are fuels such as coal and petroleum formed?

The velocity of a body moving in a straight line is increased by applying a constant force F, for some distance in the direction of motion. Prove that the increase in kinetic energy of the body is equal to the work done by the force on the body.

(a) Is it possible that a force is acting on a body but still work done is zero? Explain giving one example.

(b) Two bodies of equal masses move with uniform velocities $v$ and  $3v$ respectively. Find the ratio of their kinetic energies.

(a) Define 1 watt.

(b) An electric bulb of $60 \mathrm{W}$ is used for $6$ hours per day. Calculate the units of energy consumed in one day by the bulb.

Define work. Give its SI and CGS units. What is the relationship between these units?

Give an example for

(a) force acting in the direction of displacement.

(b) force acting against the direction of displacement.

(c) force acting perpendicular to the direction of displacement.

Define potential energy. On what factors does potential energy depend.