A pulley is fixed to the ceiling of an elevator car carries a thread whose ends are attached to masses m1 and m2.The car starts going up with an acceleration a.Assuming the masses of the pulley and the thread as well as the friction to be negligible ,find
a. acc of the load m1,relative to the elevator shaft and relative to the car;
b. the force exerted by the pulley on the ceiling of the car.
given m1>m2