Question

Force f⃗ =−10j^n is exerted on a particle at r⃗ =(7i^+5j^)m. part a what is the torque on the particle about the origin?

Answer 1

Answer:

Torque, $\tau=0i+0j-70k$

Explanation:

It is given that,

Force acting on the particle, $F=-10j\ N$

Position of the particle, $r=(7i+5j)\ m$

We need to find the torque on the particle about the origin. It is equal to the cross product of position and the force. Its formula is given by :

$\tau=r\times F$

$\tau=(7i+5j)\times (-10j)$

The cross product of vectors is given by :

$\tau=\begin{pmatrix}0&0&-70\end{pmatrix}$

or

$\tau=0i+0j-70k$

So, the torque on the particle about the origin $0i+0j-70k$. Hence, this is the required solution.