In the figure, a cord runs around two massless, frictionless pulleys; a canister with mass m = 60 kg hangs from one pulley; and you exert a force F on the free end of the cord. What must be the magnitude of F if you are to lift the canister at a constant speed?
Originally I thought this question was pretty easy. Since a=0, I thought F=mg. However, the answer (588N) is wrong.