A block of mass 25 kg is raised by a 50 kg man in two different ways a

1.	A block of mass 25 kg is raised by a 50 kg man in two different ways as shown in Fig. What is the action on the floor by the man in the two cases? If the floor yields to a normal force of 700 N, which mode should the man adopt to lift the block without the floor yielding?
Answer» In the first case man applies an upward force of 25 kg weight. Hence the action on the floor by man is = 50 kg weight + 25 kg weight = 75 kg weight = 75 × 10 = 750 N. In the second case man applies a downward force of 25 kg weight. Hence the action on the floor by man is = 50 kg weight – 25 kg weight = 25 × 10 = 250 N. (Other 500 N is applied on the ceiling) Hence man should adopt the second case.

A block of mass 25 kg is raised by a 50 kg man in two different ways as shown in Fig. What is the action on the floor by the man in the two cases? If the floor yields to a normal force of 700 N, which mode should the man adopt to lift the block without the floor yielding?

Answer»

In the first case man applies an upward force of 25 kg weight.

Hence the action on the floor by man is

= 50 kg weight + 25 kg weight = 75 kg weight

= 75 × 10

= 750 N.

In the second case man applies a downward force of 25 kg

weight. Hence the action on the floor by man is

= 50 kg weight – 25 kg weight = 25 × 10

= 250 N.

(Other 500 N is applied on the ceiling) Hence man should adopt the second case.