Question

(a) What remains constant in uniform circular motion?
(b) What changes continuously in uniform circular motion?

Answer 1

In this question, we need to comment on the constant parameter and the variable parameter in a uniform circular motion. For this, we will define the uniform circular motion and discuss the various parameters involved in the motion.

Complete answer:
(a)During a uniform circular motion an object describes a circular path with a constant speed and its distance from the axis of rotation remains constant.
(b)As the body continues its revolution, displacement from the initial position to the final position changes. An object describing a circular path changes its direction continuously due to which its velocity also changes.

Additional information:
As the velocity is changing continuously, the body experiences an acceleration which helps the body to stay in the circular path. The magnitude of the centripetal acceleration depends on the speed of the object and the radius of its circular path.
$a = \dfrac{{{v^2}}}{r}$
Where ‘a’ is centripetal acceleration, ‘v’ is the object’s speed and ‘r’ is the radius of its circular path.
According to Newton’s first law, objects do not accelerate unless acted upon by a force. Thus centripetal force is continuously acting on the body to maintain its uniform circular motion and this force acts in the direction of the center of the circle. The magnitude of centripetal force is
$F = m \times a = m \times \dfrac{{{v^2}}}{r}$
Where ‘m’ is the object’s mass and ‘a’ is its centripetal acceleration.

Note: When a body is moving in a circular path, its distance from the axis of rotation remains constant at all times but direction changes. The student should be aware of the difference between speed and velocity and should know about the factors affecting velocity and circular motion.