Question

(i) Why do porter place a round piece of cloth on their heads when they have to carry heavy loads?
(ii) Why are shoulder bag provided with broad straps?
(iii) A bottle has four holes at its bottom and all of them are at the same depth. What would happen ?

Answer 1

(1) Porter place a round piece of cloth on their heads when they have to carry heavy loads so as to increase the area on this head. Hence, the pressure on the head gets reduced. As $P=\frac{force}{area}$

(2) Shoulder bag provided with broad straps. This is because if the straps are broader, then the area will increase and hence pressure gets reduced.

(3) Pressure at some height is given by $P=\rho gh$

Where $\rho$ is the density.

$g$is acceleration due to gravity.

$h$is height of the liquid column.

The hole at the bottom will exert less pressure as compared to others.