Work-energy theorem: If a force always acts perpendicular to an object's direction of motion, that force cannot change the object's kinetic energy.

Question

Quizplus · Accepted Answer

This is a direct application of the work-energy theorem which states that the net work done on an object is equal to the change in its kinetic energy. If a force always acts perpendicular to an object's direction of motion, then the dot product of force and displacement is zero, resulting in zero net work done. Thus, the kinetic energy of the object remains constant.

Work-Energy Theorem: If a Force Always Acts Perpendicular to an Object's