Energy is the ability to do work.
So work can not be done without the transfer of energy from one body to another.
Work is the transfer of energy.
Relative motion means a motion relative to a reference point. We can also say, relative motion means motion referred or observed from a reference point.
For example, Alex is in a train and Ace is at the station, when the train starts moving, for Ace it is moving at a speed of 10 m/s, but for Alex it is moving at 0 m/s, or we can say that it is at rest for Alex, but in motion for Ace. This is relative motion.
<span>If two objects collide, each object exerts a force equal to and in the opposite direction of the other.</span>
