posted by bird .
A crank .25 long turns a shaft with a diameter of 3cm around which part of a rope is wound. One end of the rope hongs free and supports a weight of 4200nt. (a) What torque does the weight exert on the shaft? (b) What torque must be excerted on the crank to keep the system in equilibrium? (c) What force must be exerted to turn the crank?