Question

A uniform metre scale is kept in equilibrium. It is supported at 60 cm mark and a mass M is suspended at 90 cm mark as shown in the figure. What is the relation between the weight of the scale(W) and the weight of mass(M)?

• A. W > M
• B. W < M
• C. W = M
• D. Data insufficient

Answer 1

The correct option is A

W > M

Let M be the weight of the load and W be the weight of the scale.
For a body in equilibrium, the net moment is equal to zero.
Moment due to weight of the mass = M * 30
Moment due to weight of the scale = W * 10
(M * 30) - (W * 10) = 0
or M $\times$ 30 = W $\times$ 10
$\Rightarrow$ W = 3 M
Hence, the weight of the scale W is greater than that of the weight of mass M.