A metre scale is supported on a wedge at its centre of gravity. A body of weight ' $\mathrm{w}$ ' is…
A metre scale is supported on a wedge at its centre of gravity. A body of weight ' $\mathrm{w}$ ' is suspended from the $20 \mathrm{~cm}$ mark and another weight of 25 gram is suspended from $74 \mathrm{~cm}$ mark balance it and the metre scale remains perfectly horizontal. Neglecting the weight of the metre scale, the weight of the body is
20 gram-wt
15 gram-wt
33 gram-wt
30 gram-wt
Solution
Taking moments about the centre of the scale we get
$\begin{aligned}
& \mathrm{W} \times 30=25 \times 24 \\
& \therefore \mathrm{W}=\frac{25 \times 24}{30}=20 \mathrm{~g}-\mathrm{wt}
\end{aligned}$
Taking moments about the centre of the scale we get
$\begin{aligned}
& \mathrm{W} \times 30=25 \times 24 \\
& \therefore \mathrm{W}=\frac{25 \times 24}{30}=20 \mathrm{~g}-\mathrm{wt}
\end{aligned}$