Explain the statement all motion is relative.

Answer

The motion of an object is relative to either the frame of reference of the observer, or to another distinct frame of reference.

All motion is relative because every object at rest is also in motion and every object motion is in rest and these both term are related to each other... and these all depends on reference point.

for example : the car at rest is in motion with respect to earth motion

moving ball hits still ball. mover stops, hit ball moves. momentum transfer.