Question

By observing the diagram, answer the following.
a) How does the pressure at A differ from the pressure at B.?
b) The pressure at B is greater than the pressure at D. Is it true?. Justify your answer.
c) Compare the pressure at A and C.
d) If the water is replaced with mercury, how would this affect the pressure at A and D?

Answer 1

$\left(a\right)$ The pressure at $A$ is lesser than the pressure at $B$ since $P=\rho gh$ where pressure $P$ is directly proportional to height $h$. Hence, greater the height, greater shall be the pressure.

$\left(b\right)$ False, pressure at $B$ is not greater than at $D$, since pressure $P=\rho gh$ is independent of the area of container.

Since height $h$ of both $B$ and $D$ is the same, pressure at the $2$ points are equal.

$\left(c\right)$ The pressure at $A$ and $C$ are equal since they are at equal heights. Since cross-sectional area of the container does not affect $P=\rho gh$, $A$ and $C$ have the same pressure.

$\left(d\right)$ If water was replaced with mercury, the pressure at $A$ and $D$ would increase because pressure is directly proportional to density $P=\rho gh$ and since $D$ is lower than $A$, would have greater pressure than $A$.