Question

if Rod is massless, what is torque at point 'O' |​

Answer 1

Given:

A massless road is under the influence of two forces acting in different directions.

To find:

Net torque acting on the rod taking point O as the instantaneous axis of rotation.

Calculation:

Let the net torque be $\tau$.

$\sf{ \therefore \: \tau = \sum(Fd)}$

$\sf{ = > \: \tau = \{ 20 \times (2 + 2) \} - (10 \times 2)}$

$\sf{ = > \: \tau = \{ 20 \times4 \} - (10 \times 2)}$

$\sf{ = > \: \tau = 80 - 20}$

$\sf{ = > \: \tau = 60 \: N {m}^{ - 1} }$

Other things to remember:

• Torque is the rotational analogue of force.

• It is a vector unit and defined as the moment of force.

• It can be calculated by vector product between the position vector and the force vector.

• $\vec{\tau}=\vec{r}\times\vec{F}$

HOPE IT HELPS.