A closed and elevated vertical cylindrical tank with diameter 2m contains water to a depth of 0.8m.
A circular hole is made at the bottom of the tank with diameter 0.2m.As the water drains from the tank, compressed air above the water in the tank maintains a gauge pressure of 5000Pa at the surface of the water.
Ignore viscosity.How much time does it take for all the water to drain from the tank?
The Attempt at a Solution
I have no idea how to approach a problem like this in general but here is what i thought:
I can calculate water flow through a small hole using
and integrate both sides to get t.
Unfortunately, I get nowhere.Units do not match and so on.I don't know if this is even conceptually right.
Now a friend of mine says i should watch out for dh/dt rate, but I can't see how is that useful