Answer:
29.2 N
Explanation:
An object will rotate if there is a net torque. Torque is equal to the tangential force times the radius. In this case, the 10 N force exerts a clockwise torque on the pulley. To keep the pulley from rotating, it must be balanced with an equal and opposite torque, so that the net torque is zero. Therefore, we must use sum of torques to find the needed force to create that counterclockwise torque of equal magnitude.
Taking counterclockwise to be positive, the sum of torques is:
∑τ = Iα
F (0.12 m) − (10 N) (0.35 m) = 0
F = 29.2 N
The amount of force needed is 29.2 N.
