# Water flow speed through a pipe

## Homework Statement

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?

## Homework Equations

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

## The Attempt at a Solution

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

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

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).

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