Question

Water is filled in a flask up top a heightof 20 cm. The bottom of the flask is circular with radius 10 cm.If the atmospheric pressure is `1.01xx10^5` Pa, find the force exerted by the water on the bottom. Take `g=10 ms^-2` and density of water =1000 kgm^-3`.

Answer 1

The pressure at te surface of the wter is equal to the atmospheric pressure `P_0`. The pressure at the bottom is
`P=P_0+hrhog`
`=1.01xx10^5Pa+(0.20m)(1000kgm^-3)(10ms^i-2)`
`=1.0xx10^5Pa+0.02x10^5Pa`
`=1.03xx10^5Pa`.
the area of the bottom `=pi r^2=3.14xx(0.1m)^-2`
`=0.0314m^2`
The force on the bottom therefore
`=F=Ppir^2`
`=(1.03xx10^5Pa)xx(0.0314m^2)=3230N`