A man of mass 60 kg is standing on a weighing machine kept in a box of mass 30 kg as shown in the diagram. If the man manages to keep the box stationary the reading in the weighing machine is

In the given scenario, a man weighing 60 kg stands on a weighing machine inside a 30 kg box. The box is suspended by a rope passing over a pulley, with the man holding the other end to keep the system stationary.

Calculating the Reading on the Weighing Machine:

1. System Analysis:
   • Total Mass: Man (60 kg) + Box (30 kg) = 90 kg.
   • Gravitational Force: Total weight = 90 kg × 9.8 m/s² = 882 N.
2. Tension in the Rope:
   • Since the system is stationary, the upward tension (T) balances the total weight:
     • 2T = 882 N (because the rope has two segments supporting the weight).
     • T = 441 N.
3. Apparent Weight on the Weighing Machine:
   • The weighing machine measures the normal force (N) exerted by the man.
   • For the Man:
     • Downward force: Weight (W) = 60 kg × 9.8 m/s² = 588 N.
     • Upward force: Tension (T) = 441 N.
     • Apparent weight (N) = W - T = 588 N - 441 N = 147 N.