Objects at rest and in motion respond to the presence of an external unbalanced force by simple changing their magnitude of motion or position.
We have this knowledge from Newtons first law of motion "a body will remain in a state of rest or continue with uniform motion unless if it is acted upon by an external force".
When an external force acts on a body at rest, it will change the position of the body or set it motion.
For a body in motion, an external force can make they come to rest or change the motion of the body
