Question

I A 35-cm-tall, 5.0-cm-diameter cylindrical beaker is filled to its brim with water. What is the downward force of the water on the bottom of the beaker?

Answer 1

Pressure at the bottom of the beaker is $P=P_0+\rho gh$

Where $P_0$ is atmospheric pressure.

$P_0=101\,kPa=101*10^3\,Pa$

Density of water $\rho=1000\,kg/m^3$

Height of cylinder $h=35\,cm=0.35\,m$

Radius of cylinder $r=2.5\,cm=0.025\,m$

$P=P_0+\rho gh=101*10^3+(1000*9.81*0.35)=104433.5\,Pa$

Downward force of water at the bottom of beaker $F=PA=P(\pi r^2)=104433.5*\pi *(0.025)^2=205\,N$