(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Water is supplied to a building through a pipe of radius R = 3.0cm. In the building, a faucet tap of radius r = 1.0cm is located 2.0m above the entering pipe. When the faucet is fully open, it allows us to fill a 25-L bucket in 0.5 minutes. What is gauge pressure in the pipe entering the building? Assume no other faucets are opened during the experiment.

2. Relevant equations

ΔV/Δt = A*v

A1v1 = A2v2

p1 + 1/2ρ(v1^2) = p2 + 1/2ρ(v2^2) (Bernoulli's law)

pgauge = p - patm

3. The attempt at a solution

Using the first two equations I have determined that v1 = 0.3 m/s and v2 = 2.7 m/s. Now I am unsure how to apply Bernoulli's law when I am missing one of the pressures. When I try to use atmospheric pressure (101325 Pa) as one of the pressures, I do not get the correct gauge pressure, which is 23 kPa. I really just need a push in the right direction! Thank you.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Bernoulli's law for water coming out of a faucet

**Physics Forums | Science Articles, Homework Help, Discussion**