Question

A body "A" of weight 10 kg with its center of gravity 25 cm from the axis of rotation is to be balanced by another body ‘B’ of weight 5 kg. The radius at which the center of gravity of weight ‘B’ should be placed is
1. 12.5 cm
2. 2 cm
3. 50 cm
4. None of these

Answer 1

Correct Answer - Option 3 : 50 cm

Concept:

For the balancing of the two bodies, 

the centrifugal force should be same, i.e. F₁ = F₂

⇒ (mrω²)₁ = (mrω²)₂

The speed of both bodies is same,

Therefore, (mr)₁ = (mr)₂

Calculation:

Given:

m₁ = 10 kg, r₁ = 25 cm, m₂ = 5 kg

⇒ 10 × 25 = 5 × r₂

⇒ r₂ = 50 cm