Question

Why does the school bags have broad shoulder straps?
(A) To increase pressure
(B) To decrease pressure
(C ) As a fashion trend
(D) None of the above

Answer 1

Hint: The pressure is related to the surface area. Hence, when the straps of the bags have larger surface area its pressure decreases. As the pressure on the shoulder is less, it will be easier for the students to carry the bag. Thus the pressure is the ratio of force to the area. Hence the pressure and area are inversely proportional.

Formula used:
The pressure and area are related to each other by,
$P=\dfrac{F}{A}$
where, P is the pressure
F is the force
A is the area

Complete answer:
The pressure and area are related to each other by the relation $P=\dfrac{F}{A}$, where P is the pressure, F is the force and A is the area. Thus the pressure is the ratio of force to the area. Hence the pressure and area are inversely proportional. Thus we can say that as the area of the cross section increases the pressure decreases and as the cross sectional area decreases its pressure increases. For this reason in order to reduce the pressure bag straps are made of larger cross sectional area. That also helps to carry the school bags easier for the students.

Hence option (B) is correct.

Note:
Thus we can say that the pressure is related to the surface area. Hence, when the straps of the bags have larger surface area its pressure decreases. As the pressure on the shoulder is less, it will be easier for the students to carry the bag. Thus the pressure is the ratio of force to the area. Here the pressure and area are inversely proportional.