Question

A particle is attached to an end of a rigid rod. The other end of the rod is hinged and the rod rotates
always remaining horizontal. It's angular speed is increasing at constant rate. The mass of the particle
is 'm'. The force exerted by the rod on the particle is F, then
(A) F>mg
(B) F is constant
(C) The angle between F and horizontal plane decreases.
(D) The angle between F and the rod decreases.​

Answer 1

The angle between F and the rod decreases.​

Option (D) is correct.

Explanation:

• The rotation in the particle is produced by the rod. The rod exerts a force "F" on the particle and the velocity of the particle changes due to which angular speed of the particles also increases.
• The particle has tangential acceleration and radial acceleration.
• As the speed of the particle increases the tangential acceleration also increases.
• But the angle between force and rod decreases.