Physics
Physics · mechanics
Problem
A large, closed upper tank contains water at the manometric pressure of: , exerted by compressed air. A hole is made in the side wall, 3 m below the water level. Calculate the exit speed of the water through the hole.Intuitive explanation
The key is recognizing that water exits due to the combined pressure from both the compressed air above and the weight of the water column itself. Use Torricelli's principle—the exit speed depends on the total pressure head pushing the water out, which you can find by converting the air pressure into an equivalent water column height, then adding the actual depth of the hole below the surface. This gives you the effective height to use in the energy equation.
Intuitive explanation
The key is recognizing that water exits due to the combined pressure from both the compressed air above and the weight of the water column itself. Use Torricelli's principle—the exit speed depends on the total pressure head pushing the water out, which you can find by converting the air pressure into an equivalent water column height, then adding the actual depth of the hole below the surface. This gives you the effective height to use in the energy equation.