Q5.32 A block of mass 25 kg is raised by a 50 kg man in two different ways as shown in Fig. 5.19. 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?
Using Newton's law force applied on the block:-
or
Weight of man = 500 N
Case 1:- When a man is lifting block directly, man is applying force in the upward direction directly.
The net force on floor : - 250 + 500 = 750 N
Case 2:- When a man is lifting block through pulley :
The net force on floor :- 500 - 250 = 250 N
Now it is given that the floor can yield 700 N of the normal force. Thus the man should adopt case 2.