Question 150: Centre of Mass and Rotational Motion

Question

The torque of a force $$5 \hat{i}+3 \hat{j}-7 \hat{k}$$ about the origin is $$	au$$. If the force acts on a particle whose position vector is $$2 i+2 j+k$$, then the value of $$	au$$ will be

Accepted Answer

$\vec{	au}=\left|\begin{array}{ccc}\hat{i} & \hat{j} & \hat{k} \ 2 & 2 & 1 \ 5 & 3 & -7\end{array}ight|$
$$
\begin{aligned}
&=\hat{i}(-14-3)+\hat{j}(5+14)+\hat{k}(6-10) \\
&=-17 \hat{i}+19 \hat{j}-4 \hat{k}
\end{aligned}
$$

Answer

$$11 \hat{i}+19 \hat{j}-4 \hat{k}$$

Answer

$$-11 \hat{i}+9 \hat{j}-16 \hat{k}$$

Answer

$$-17 \hat{i}+19 \hat{j}-4 \hat{k}$$

Answer

$$17 \hat{i}+9 \hat{j}+16 \hat{k}$$

Centre of Mass and Rotational Motion

The torque of a force $5 \hat{i}+3 \hat{j}-7 \hat{k} about the origin is \tau. If the force acts on a particle whose position vector is 2 i+2 j+k, then the value of \tau$ will be

Choose the correct answer: