Final answer:
In uniform circular motion, a centripetal force causes an object to move in a circle at a constant speed, resulting in centripetal acceleration. A magnetic force, which remains perpendicular to velocity, does not do work but changes the direction of motion.
Step-by-step explanation:
A body moving in a perfectly circular path at constant speed does indeed experience forces. This is clear because, even though the speed remains constant, the direction of the velocity changes, indicating that there is an acceleration. This acceleration is known as centripetal acceleration, and it is caused by a net external force termed the centripetal force.
The centripetal force acts towards the center of the circular path and keeps the object moving in a circle. It's essential to understand that while this force does work in rotational motion, as it causes displacement, a magnetic force, which is always perpendicular to a charged particle's velocity, does not do work on the particle. Instead, a magnetic force merely changes the direction of motion, keeping the particle's kinetic energy and speed constant in uniform circular motion.