Question

A stone tie with a string held at one end is being rotated at a constant angular velocity in the air. The tangential velocity will remain constant if _______

(a) The plane of motion of the stone is parallel to the ground

(b) The plane of motion of the stone is perpendicular to the ground

(c) The plane of motion of the stone is at an angle of 45 degrees to the ground

(d) The tangential velocity is independent of the plane of motion

This question was posed to me by my college professor while I was bunking the class.

My question is from Non-Uniform Circular Motion in chapter Laws of Motion of Physics – Class 11

Answer 1

Right answer is (a) The plane of motion of the stone is parallel to the ground

The explanation: When the plane motion of the stone is parallel to the ground, the tangential velocity experiences acceleration in two directions, one towards the centre and other towards the ground. Both these directions are perpendicular to the direction of the tangential velocity. Hence the tangential velocity will not change.