# Homework Help: Question asking me to show that the water flow rate is approximately 26kg\s

1. Dec 5, 2011

### Euansmith

1. A farmer builds a water storage tank 12m above ground.

The water is fed via a 200m long, 125mm diameter pipe to a field for irrigation purposes. The pipe has a friction factor of 0.008. Using the K data below, show that the water flow rate (kg/s) in the pipe is approximately 26kg/s.
Data
K factors: Tank exit 0.5, Bend 0.9, valve 1.0 Water density: 1000kg/m3

2. Dec 5, 2011

### Euansmith

So far I understand how to use Bernoulli's equation, and how to use Darcy's equation to obtain the frictional loss of the pipe, but I can't actually do them because I have two unknowns. Those being velocity and frictional head loss.

I know that to find volume flow rate you multiply the velocity by the cross sectional area of the pipe. Then I guess to find the water flow rate in kg/s I will have to take the flow rate and divide 1000 by it. (1000kg of water per cubic metre.) If someone could point me in the right direction I would be most appreciative.

Cheers,

Euan.

3. Dec 6, 2011

### LawrenceC

Attempt a trial and error solution until a certain equation balances.