The force exerted by mercury on the bottom of the tube can be calculated as:
F=P0A+ρmghA
where:
- P0=105Nm−2 (atmospheric pressure),
- A=πr2=722×(2×10−2)2 (area of the base),
- ρm=1.36×104kg m−3 (density of mercury),
- g=10ms−2,
- h=30×10−2m (height of mercury column).
Calculating A:
A=722×(2×10−2)2
Substitute into the force equation:
F=105×722×(2×10−2)2+1.36×104×10×(30×10−2)×722×(2×10−2)2
Solving this:
F=51.29+125.71=177N.