Question

In uniform circular motion the velocity of a particle is:

• A. constant
• B. variable in magnitude
• C. variable in direction
• D. both a) and b)

Answer 1

Answer: (C)

variable in direction

Velocity is a vector quantity, has both magnitude and a direction. The magnitude of the velocity vector is the instantaneous speed of the object. The direction of the velocity vector is directed in the same direction that the object moves. Since an object is moving in a circle, its direction is continuously changing. At one moment, the object is moving northward such that the velocity vector is directed northward. One-quarter of a cycle later, the object would be moving eastward such that the velocity vector is directed eastward. As the object rounds the circle, the direction of the velocity vector is different than it was the instant before. So while the magnitude of the velocity vector may be constant, the direction of the velocity vector is changing. hence velocity is variable in a uniform circular motion