Question

Consider the following two statements A and B and identify the correct choice.
A) When a body is rotated along a vertical circle with uniform speed then the sum of its kinetic energy and potential energy is constant at all positions
B) To make a body to move along a vertical circle, its critical speed at any point is independent of mass of body

• A. A is true but B is false
• B. A is false but B is true
• C. Both A and B are true
• D. Both A and B are false

Answer 1

The correct option is B A is false but B is true

When a body is rotated in a vertical circle with uniform speed its kinetic energy is constant because of uniform speed. Its potential energy changes because of change in height. Hence the sum of P.E + K.E won't be same.
To make a body moving in a vertical circle the critical velocity at a point is independent of mass. Critical velocity for bottommost point is sqrt(5rg).