# Homework Help: Water flow speed through a pipe

1. Nov 8, 2011

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

Water flows through a 1.3 cm diameter pipe into a 295 L bathtub, which it fills in 5 min.

What is the speed of the water in the pipe?
2. Relevant equations

V_in=v_L*t*A_L (Equation I got in my class lecture, I think its a variation of bernoulli's.)

3. The attempt at a solution

Solved for v_L in that equation, but thats not correct.

2. Nov 9, 2011

### SteamKing

Staff Emeritus
Did you check your units? You are given liters, cm, and minutes. What units are used for velocity?

3. Nov 9, 2011

### zgozvrm

Clearly, the speed of the water in the pipe was
$$\frac{295\ \ell}{5\ min} = 59\ \ell/min$$

But, I'm guessing you're looking for linear speed, not volumetric speed? (something along the line of 5 cm/sec, for instance).

4. Nov 9, 2011

### RTW69

Actually 59 l/min is the volumetric flow rate which will equal velocity * cross sectional area of pipe. To make the units turn out correctly you will need to convert liters to cubic meters