Question

How does pressure exerted by solid and a fluid differ?
A. A solids exert pressure only on its base downwards while a fluid exerts pressure at all points in every direction.
B. A liquid exerts pressure only on its base downwards while a solid exerts pressure at all points in every direction.
C. Both exerts pressure on its base downward.
D. Both exerts pressure at all points in all directions.

Answer 1

Hint:As we all know that to find the intensity of force, we must apply it on a body. The force applied is just the effort; its effect depends on the part of the object it is applied. For example, a force applied by a hammer on the body and a force applied by a pin on the body, both have different effects.

Complete step by step answer:
We should keep in mind that pressure is the force applied to the unit area of the surface. Pressure can be represented as:
$P = \dfrac{F}{A}$
Here $P$ are the pressure, $F$ is the force applied, and $A$ is the surface area. Therefore, we can see that pressure depends on force and surface area.
Pressure has the characteristics of the proportionality factor. The area is something which gives us the direction and pressure is defined everywhere in the volume of the bulk and not just only at the surface. Gas inside the container has pressure everywhere overall the bulk volume.
We can say that pressure is a tensor but frankly speaking that for isotropic gas it is a scalar.
Pressure depends on the force applied and surface area of the body for a body.
A solid applies pressure only at the point of contact downwards due to weight of the body, but in case of a fluid, the pressure plays a role as a tensor and at one point is has values in all directions.
Therefore, A solid exerts pressure only on its base downwards while a fluid exerts pressure at all points in every direction, and the correct option is (A).

Note:As we all know that pressure is directed normally towards the surface area, it has only one direction that is normal to the surface than in that case it is scalar. But if both the force and area has directions then, in that case, it is no more scalar, and it becomes a tensor, and in that case, we are talking about the negative of the stress tensor. This is because, at many times, we refer to stress tensor as pressure tensor.