Question

Two cylindrical vessels fitted with pistons A and B of area of cross section 8 $c{m}^2$ and 320 $c{m}^2$ respectively are joined at their bottom by a tube and they are completely filled with water. When a mass of 4 kg is placed on piston A, find: (i) the pressure on piston A , (ii) the pressure on piston B, and (iii) the thrust on piston B.

Answer 1

Given

Force applied to the smaller piston A$=4kg$

Area of cross section of piston A$=8c{m}^2$

Area of cross section of piston B$=320c{m}^2$

(i) Pressure acting on piston A in the downwar direction$=\frac{Thrust}{Area}$

$=\frac{4}{8}=0.5kg/c{m}^2$

$\therefore$ Pressure acting on piston A$=0.5kg/c{m}^2$

(ii) according to pascal's law

Pressure acting on piston A= Pressure acting on piston B$=0.5kg/c{m}^2$

(iii) Thrust acting on piston B in the upward direction$=Presuure\times AreaofB$

$=4\times \frac{32}{8}=160kg$

$\therefore$ Thrust acting on piston B in the upward direction$=160kg$