Explain why it is important to identify a reference point for any description of motion

An object can be said to be in motion if there is a change in its initial position relative to a reference point.

Explanation:

A reference point could be a place or something that can be used to determine if an object is in motion relative to it. Thus, the reference point make us to understand the properties (type, distance and direction) of the motion.

Also, motion of any object can be explained using an inertial frame. This frame considers its relative motion with respect to a reference point.

truck y has a greater velocity than truck x.