physics
posted by please help!!!! .
A square pool with 100mlong sides is created in a concrete parking lot. The walls are concrete 87 cm thick and have a density of 2.5 g/cm3. The coefficient of static friction between the walls and the parking lot is 0.42. What is the maximum possible depth of the pool? (The density of water is 1000 kg/m3.)

The horizontal pressure on the wall is densitywater*g*depth/2
The force of friction on wall is
mu*densityconcrete*depth*.87*100*g
setting these two equal
pressure*area=frictionforce
densitywater*g*depth/2*depth*100=mu*denstiyconcrete*g*depeth*.87*100
depth=2*.87*mu*densityconcrete/densitywater. check my math.