# Water Flow

1. Dec 4, 2008

### Husker70

1. The problem statement, all variables and given/known data
A horizontal pipe 10.0cm in diameter has a smooth reduction to a pipe
5.00cm in diameter. If the pressure of the water in the larger pipe is
8.00x10^4Pa and the pressure in the smaller pipe is 6.00x10^4Pa, at
what rate does water flow through the pipes?

2. Relevant equations
A = pie(r)^2
Kinematics equation to find velocity
A1V1 = A2V2
F=PA

3. The attempt at a solution
I got areas first
A = pie(5.00cm)^2 = 78.5cm^2
A = pie(2.50cm)^2 = 19.6cm^2

Then I found F using F=PA
F = (8.00x10^4Pa)(78.5cm^2) = 6.28x10^6N
F = (6.00x10^4Pa)(19.6cm^2) = 1.18x10^6N

I'm not sure what kinematics equation to use to find velocity
Thanks,
Kevin
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Dec 4, 2008

### rl.bhat

Using Bernoulli's equation you can wright P1+1/2*p*V1^2 = P2 + 1/2*p*V2^2
By using the equation A1V1 = A2V2 you can solve for V1 and V2

3. Dec 4, 2008

### Husker70

I'll try it thanks