# Finding all the pressure acting on base of cylidner

Water is filled in a flask up to a height of 20 cm. The bottom of the flask is circular with radius 10 cm. If the atmospheric pressure is $$1.013 \times 10^5$$ Pa,find total force exerted on the bottom of flask. Take g = 10 ms-2 and density of water = 1000 kgm-3. P0 is atmospheric pressure here.

Now, here if I draw the FBD of the base of flask. Then, there are three pressures acting on the base. Atmospheric pressure acting from top and below because fluids exerts pressure in all directions. Then is the hpg pressure.

Total pressure on the bottom of flask is $$P_0 -P_0 + hpg$$. Is this correct if it asked total pressure acting on the base?

From the inside of the flak the pressure is $$P_0+ hg\rho$$.
If you are looking for the force that secrets force on the base then that force is $$(P_0+ hg\rho- P_0 )A$$.
• the second equation describes the force that you need to use when you are doing structural calculations. there is a subtle difference between them. In the first $P_0$ is included. In the second it isn't. Jan 23 at 19:40