Pressure on sides and ends of pool, given the pools dimensions and depth

AI Thread Summary
The discussion focuses on calculating the pressure exerted by water on the sides and ends of a swimming pool with specific dimensions and a water depth of 2.30 m. The correct formula for pressure is highlighted as P = ρgz, where ρ is the water density, g is gravity, and z is the depth. The initial attempts to calculate the force on the sides using incorrect equations are noted, indicating a misunderstanding of the relationship between pressure and force. The correct approach involves first determining the pressure at the bottom of the pool and then using that to find the force on the sides and ends. Accurate calculations are essential for understanding the forces acting on the pool structure.
denxnis
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Homework Statement


A swimming pool has dimensions 34.0 m 9.0 m and a flat bottom. When the pool is filled to a depth of 2.30 m with fresh water, what is the force caused by the water on the bottom?

I have the answer to this which is 6.90 x 10^6, however I cannot figure out the pressure on the sides or ends.

Homework Equations


Pressure on bottom = water density X gravity x area

The Attempt at a Solution


I understand the water depth has to play into this somehow but I cannot figure out how...
I attempted 9.80 x 2 x 9 = 176.4 kN
and
9.80 x 2 x 34 = 666.4 kN

These were incorrect
 
Last edited:
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Your relevant equation is wrong.
Check it.
 
Apologies,
ρ = density - P = pressure - F = force - b = bottom of pool -
z = area of pool
Pb = ρgz
Fb = PbA
 
z is the depth of the water. Now find the pressure at the bottom Pb and then Fb
 
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Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
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