# If a cylindrical tank of radius 1m rests on a platform 5m above the

1. Nov 21, 2009

### jeedoubts

If a cylindrical tank of radius 1m rests on a platform 5m above the ground. Initially the tank is filled with water up to a height 5m. A plug whose area is 10-4m2 removed from an orifice on the side of the tank at the bottom.(density of water = 103kg/m3, g= 10m/s2).
i wanted to ask what would be the initial force applied by water coming out from orifice on tank???

2. Nov 21, 2009

### HallsofIvy

Re: Fluids

The force is pressure times area- the water pressure times the area of the opening. The pressure is weight of water above the bottom divided by the area of the bottom- and since the weight of the water is just g times the density times the volume, which is itself base area times height, the pressure is just g times the density of water times the height of the tank. So the force at the opening is g times the density of water times the height of the tank times the area of the opening. Strictly speaking, since pressure changes with height and the opening is vertical, you should integrate over the area of the opening, but with it only few mm in diameter, just multiplying by the area is good enough.

3. Nov 21, 2009

### jeedoubts

Re: Fluids

So the answer must be 5N but the answer is 10N can you explain this???