# Homework Help: Help using Bernoulli's equation

1. Nov 23, 2009

### lilmul123

1. The problem statement, all variables and given/known data

Water flows at 0.61 m/s through a 3.0 cm diameter hose that terminates in a 0.30 cm diameter nozzle. Assume laminar non-viscous steady-state flow.

(a) At what speed does the water pass through the nozzle? (Correctly solved to be 61 m/s).

(b) If the pump at one end of the hose and the nozzle at the other end are at the same height, and if the pressure at the nozzle is 1 atm, what is the pressure at the pump in atm?

2. Relevant equations

P1 + .5p(v1)^2 = P2 + .5p(v2)^2

P1 = Looking for this
p = 1000 kg/m^3 ??
v1 = .61 m/s
v2 = 61 m/s
P2 = 1 atm

3. The attempt at a solution

I plugged in all known variables, but P1 ended up being a very large number (1860314.95 atm), and this was incorrect. I'm thinking that possibly the density that I'm using is incorrect. Can anyone see what I am doing incorrectly?

2. Nov 24, 2009

### Redbelly98

Staff Emeritus
Most of your quantities are in metric (MKS) units, so the pressure will have to be converted to those units first.

3. Nov 24, 2009

### lilmul123

Thanks! I wasn't sure about those units either.