Mass of the block, m = 25 kg
Mass of the man, M = 50 kg
Acceleration due to gravity, g = 10 m/s2
Force applied on the block, F = 25 × 10
= 250 N
Weight of the man, W = 50 × 10 = 500 N
Case (a): When the man lifts the block directly
In this case, the man applies a force in the upward direction.
This increases his apparent weight.
Action on the floor by the man = 250 + 500 = 750 N
Case (b): When the man lifts the block using a pulley
In this case, the man applies a force in the downward direction. This decreases his apparent weight.
Action on the floor by the man = 500 – 250
= 250 N
If the floor can yield to a normal force of 700 N, then the man should adopt the second method to easily lift the block by applying lesser force.