Question

23. Give reasons for the following:
(a) A porter carrying heavy boxes generally places a round piece of thick
cloth on his head.
(b) A fireman feels difficulty in holding a hosepipe which ejects large
amount of water at high speed.​

Answer 1

Answer:

ans a)a Porter carries heavy boxes inn a round piece of cloth so as to increase the surface area between his head and load which results in decrease in pressure on his head as

$pressure = \frac{force}{area}$

here force us nothing but the weight of boxes.

ans b) According to Newton's third law of motion every action has equal and opposite reaction so same amount of force is exerted on fireman that is released from pipe which makes fireman feel difficulty