Ok, so what is the physical picture here. What's going on? How would the groundwater exert an upward force on the tank?
I am stumped, could anyone be of assistance?
"What is the upward force on the bottom of an empty underground storage tank caused by a groundwater depth of 5 feet above the tank bottom? The tank is 8 feet wide and 16 feet long."
Another approach is using pressure. The pressure at the bottom of the tank is given by:
where h is the depth of water,
rho is the density of water,
g the acceleration due to gravity.
Then, we know that
where A is the area of the tank which is affected by the pressure, that is the bottom area of the tank,
and F the force acting on the tank.
Don't complicate a simple problem.If the water is in the tank its weight is the upward force for water alone (tank weight excluded) When water is in the ground the pressure pushing up equals 5 ft of water. Answer is approx 40000 lbs 5x8x16x62.5