Pressure, force, and Area: Calculating the net Force Applied on A dam by Water

[Beginner@Phys]

Homework Statement

Water stands at depth d behind a dam of width w . Find an expression for the net force of the water on the dam. Express your answer in terms of the variables w,d,p (density), and appropriate constants.

Homework Equations

P=F/A or pressure=Force/Area
Hydrostatic pressure: p=p_0+pgd

The Attempt at a Solution

Fnet=P*A=(pgd)*A =pgd*w*d

I guess that p_0 cancels out, because atmospheric pressure is felt both by the dam and the water. Does this make sense?

 

[Doc Al]

The Attempt at a Solution

Fnet=P*A=(pgd)*A =pgd*w*d

Careful. Is the pressure the same at every depth?

I guess that p_0 cancels out, because atmospheric pressure is felt both by the dam and the water. Does this make sense?

That part makes sense.