Question

Two masses are attached to a rod end to end. If torque is applied, they rotate with angular acceleration α. If their distances are doubled and same torque is applied, then they move with angular acceleration

(a) 4α

(b) α

(c) 3α

(d) α/4

Answer 1

Correct option (d) α/4

Explanation :

Suppose the masses m₁ and m₂ are attached to the ends of a massless rod. C₁ is the axis of rotation which is at a distance R from each of the masses.

.'. The moment of inertia of the system,

Now if the distance between the masses is doubled, then the moment of inertia,

Since the same torque is applied in both the cases,