Question

An object performs a uniform circular motion, then

Statement-1: the velocity of the object is constant.

Statement-2: the magnitude of the acceleration of the object is constant.

• A. Statement -1 is true and statement -2 is false
• B. Statement-1 is false and statement-2 is true.
  
• C. Statement -1 is true and statement-2 is true.
• D. Statement -1 is false and statement-2 is false.

Answer 1

The correct option is B

Statement-1 is false and statement-2 is true.

Statement-1: The velocity of the object is constant.

1. If a body moves in a uniform circular motion the speed of the object will remain constant.
2. As velocity is dependent on the direction of motion, it keeps on changing due to the centripetal force.
3. Therefore the statement is false.

Statement-2: The magnitude of the acceleration of the object is constant.

1. As the direction of the object changes at each point in a circular motion.
2. And acceleration is defined as the rate of change of velocity.
3. Here, velocity is changing but the magnitude of velocity that is speed is constant.
4. Therefore, the magnitude of the acceleration is also constant.
5. So, speed and magnitude of acceleration remain constant.

Therefore, Statement -1 is true and statement-2 is true.

Hence, the correct option is (B).