Question

Two cylindrical vessels fitted with pistons A and B of area section $8c{m}^{2}and320c{m}^2$ respectively , are joined at their bottom by a tube and they are completely filled with water. When a mass of 4kg is placed on piston A, find the thrust on piston B,

Answer 1

Pressure is given by, $P=\frac{Force}{Area}$

But from Newton's second law we have, $F=Ma$

Here we have, $a=g=10m/s^2$

$\therefore F=4\times 10=40N$

(i) The pressure on piston A will therefore be given by, $P_a=\frac{40}{8}$

or, $P_a=5Pa$.

ii) For pressure on piston B we have,

$P_a=P_b$

$\frac{F}{A_1}=\frac{F_2}{A_2}$

or, $\frac{40}{8}=\frac{F_2}{320}$

or, $F_2=320\times \frac{40}{8}$

or, $F_2=320\times 5$

or, $F_2=1600N$

The thrust will be equal to the force on piston be which is $1600N$