Question

What do we know about the net total of all the torques applied to a system thatis free to rotate about a pivot point if that system is in a balanced condition (notrotating)?

Answer 1

If torque is applied to a system that is in equilibrium we notice that there is no rotation, therefore, there is no angular acceleration. The equation for the net torque is:

$T=I\alpha$

Where

$\begin{gathered} T=\text{ net torque} \\ I=\text{ moment of inertia} \\ \alpha=\text{ acceleration} \end{gathered}$

Since there is no rotation we have:

$\alpha=0$

Substituting in the formula for torque:

$T=0$

Therefore, the net torque is zero when the system is in equilibrium.