The pulley arrangements shown in figure are identical, the mass of the rope being negligible. In case I, the mass m is lifted by attaching a mass 2m to the other end of rope while in the second case the rope is pulled with a constant downward force F = 2mg, where g is acceleration due to gravity. The acceleration of mass m in case I is
T = 2mg also T–mg = ma1 Finally a < a1