Question

A thin rod of length 3 L is bent at right angles at a distance L from one end. Locate the centre of mass of the arrangement w.r.t the corner (see figure). (Given, L=1m)

• A. $r_{COM}=(0.2\hat{i}+0.8\hat{j})$m
• B. $r_{COM}=(0.4\hat{i}+0.6\hat{j})$m
• C. $r_{COM}=(0.5\hat{i}+\hat{j})$m
• D. $r_{COM}=(0.2\hat{i}+0.6\hat{j})$m

Answer 1

The correct option is C $r_{COM}=(0.5\hat{i}+\hat{j})$m

$\begin{array}{c}{x}_{com}=\frac{L}{2}\hat{i}=0.5\hat{i}\\ y_{com}=\frac{2L}{2}\hat{i}=\hat{j}\end{array}$

$\therefore r_{com}=\left(0.5\hat{i}+\hat{j}\right)m$

hence, the option $C$ is correct .