How to Calculate Water Velocity and Pressure in a Building's Plumbing System?

[Keithkent09]

Homework Statement

The water supply of a building is fed through a main pipe 4.00 cm in diameter. A 2.00 cm diameter faucet tap, located 2.10 m above the main pipe, is observed to fill a 28.0 L container in 30.0 s.
(a) What is the speed at which the water leaves the faucet?

(b) What is the gauge pressure in the 4.00 cm main pipe? (Assume the faucet is the only "leak" in the building.)

Homework Equations

pressure=density*g*h
pressure=F/A

The Attempt at a Solution

I really did not know where to start with this problem. I think the velocity is just supposed to be found by converting liters into meters. I think the conversion factor is about 3.18, with that I got the velocity to be about 23.7 m/s. I was not sure how to handle part b of the problem.

 

[AEM]

Two quick comments:

(1) Reduce all dimensions to the same units, say meters.

(2) You can't convert liters (a volume) into meters (a length)

 

[Keithkent09]

I actually figured this problem out and got the correct answer thanks for your help.