Two masses of I kg and 5 kg are attached to the ends of a massless string passing over a pulley of negligible weight. The pulley itself is attached to a light spring balance as shown in figure. The masses start moving during this interval; the reading of spring balance will be:

Suppose T be the tension in each part of the string passing over the pulley. Iis given by:T = 2m1m2gm1+m2 = 2×1×51+5g = 53gFor equilibrium of the pulley there is an upward force of 2T acting on the string joining the pulley to the spring. Therefore, reading of spring balance will be 2T = 103 Kgf . So reading will be 103 kgf which is less than 6 kgf .