Describe the motion of an object that possesses kinetic energy yet undergoes no net displacement.

As per the question  the body possesses kinetic energy but the net displacement of the particle is zero.

Before going to explain the type of motion first  we have to know the basics of displacement.

The displacement is a vector quantity which has magnitude as well as direction .it is the minimum distance between two points out of all possible paths

Let us consider an example .let a body travels from point A to the point B and again comes to the back to the same point A .here the distance traveled is 2AB but the net displacement is zero.we have to apply this concept to solve this problem.

As the body possesses kinetic energy but the net displacement is zero .

This is in case of an circular motion.in circular motion the body possesses rotational kinetic energy but in every circular rotation ,the net displacement is zero.

One can take an example of oscillatory motion also.here the particle possesses vibrational kinetic energy ,but in each vibration ,the net displacement is zero.

be subject to a force andchange its motion

probably not the "magnets"in the magnet, so to speak, are thought to be electrons orbiting in shells. vurrent loops two sides to the loop