Is pressure under a 100 meter tall dam greater than the pressure 100 meter down the ocean?

Question

I think pressure depends on the pressure of water column + atmospheric pressure above a unit area. Dam has huge potential energy due to height above sea level and hence large pressure is applied to the walls of the dam. Does it in any way affect the pressure in the bottom of the dam. This question may sound stupid. But I failed to find the exact mathematical formulas to prove it.

Answer

no. the water pressure in the ocean is greater then the water pressure of a dam cause you gotta look at it from my way cause if i stand on dam it does nothing to me, but if i am in the ocean water pressure is acting on my from every direction

Answer

Water Pressure = density x gravity x depth 

And of course pressure acts equally in all directions from one point.

What you may need to consider is :-

1. Sea water is not as dense as fresh water.
2. Atmospheric pressure at sea level is higher (taller column of air resting on it), than the higher Dam.

You are correct to add the atmospheric pressure to get total pressure (rather than that pressure difference between the surface & at 100m, but this small amount is insignificant due to the massive difference between the density of air & water . 

If you were asked to consider the total energy, the you would add the potential energy the water due to height.

Is pressure under a 100 meter tall dam greater than the pressure 100 meter down the ocean?

Answers (2)