Answer
$f_s=843N$
Work Step by Step
Since the torque $\tau$ balances the countertorque $\tau'$, we have $$\tau'=\tau=295N.m$$ $$f_sl=295N.m$$
Since the axis of rotation is at the center of the wheel, the lever arm is the radius of the wheel, so $l=0.35m$. Therefore, $$f_s=\frac{295N.m}{0.35m}=843N$$
