What is defined as the motion of an object in a circular path at constant speed?

The motion of an object in a circular path at constant speed is best described as circular motion. This type of motion involves an object traveling along a circular trajectory, where the distance from the center of the circle remains consistent, and the speed does not change.

In circular motion, although the speed is constant, the direction of the object is continually changing. This continuous change in direction means that there is an acceleration acting on the object, directed towards the center of the circle, known as centripetal acceleration. The forces involved can be tension, gravity, or friction, depending on the specific situation.

Linear motion refers to movement in a straight line, which does not apply when an object is traveling in a circular path. Orbital motion refers specifically to the movement of objects around a gravitational body, such as planets around the sun, which involves not just circular but elliptical paths as well. Periodic motion describes any motion that repeats at regular intervals, which can include circular motion but applies more generally to various types of repetitive movements.

Thus, circular motion is the most specific and accurate term for the situation described in the question.