You are to design a rotating cylindrical axle to lift buckets of cement of 775 N from the ground to a rooftop 69.5 m above the ground. The buckets will be joined to a hook on the free end of a cable which wraps around the rim of the axle; as the axle turns, the buckets will increase.
(i) What must the diameter of the axle be in order to increase the buckets at a steady 1.65 cm/s if it is turning at 7.8 rpm?
(ii) If rather the axle should give the buckets an upward acceleration of 0.450 m/s2, what must the angular acceleration of the axle be?