Posted by matt on Tuesday, November 13, 2012 at 2:12pm.
The pressure in a fire hose is 20 atm. How high can a firefighter spray water from this hose?
One atm is about 1×105 Pa. The density of water is 1.0 g/ml, or 103 kg/m3. The acceleration of gravity, g, is 9.8 m/s2.

physics  matt, Tuesday, November 13, 2012 at 2:23pm
Water is flowing through a horizontal pipe at a rate 0.2 m3/s. The pipe narrows from a radius of 10 cm to 4 cm. What is the change in pressure?