For an object under uniform circular motion, which of the following remains constant?

The correct answer is option 4) i.e. All of the above

CONCEPT:

• Uniform circular motion is where a moving object traces a circular path with constant speed.
  • ​A circle is assumed to be a polygon with infinitely many sides such that each side approximates to a point.
  • So, the object moving on a circular path undergoes a change in direction at every point.
  • Since direction changes and speed remains constant, velocity is varying.
• Kinetic energy is the measure of energy possessed by a moving object.

It is given by the equation KE = \(\frac{1}{2}mv^2\)

EXPLANATION:

Given object is under uniform circular motion.

• An object under uniform circular motion has a constant speed.
• In a uniform circular motion, the magnitude of velocity is uniform but the direction keeps changing at every point. So, the magnitude of acceleration is constant.
• Kinetic energy is proportional to the magnitude of the velocity of a moving object ⇒ KE ∝ v². Hence, kinetic energy remains constant in a uniform circular motion.

Confusion Points

• Only the magnitude of velocity is considered for kinetic energy. 
• Kinetic energy is a scalar quantity.