- #1

member 731016

For this fluid statics problem,

One of the answers is:

However, why did they assume the pressure at the top was zero? I thought the pressure at the top would be 1 atm?

So tried to take atmospheric pressure into account putting 1 atm at the top,

Do you please know how to get P_0A/2 so that the P_0A/2 terms can cancel to get their hydrostatic force? I assume that the atmospheric pressure is the same at the top and bottom since the height of the dam is negligible to the scale of the atmosphere.

Many thanks!