# Mass/Density problem - please check my working.

bentleyq
1. An olympic pool is 50m long 25m wide and a minimum average depth of 2m
a) If the pool is filled as specified, what is the mass of water? Denisty of water to be 1.0g/cm^3
b) How long will it take to fill the pool from a standard garden hose, if the flow rate from hose has average of 8 liters per minute?

2. Homework Equations (density = mass/volume)(volume = LxWxH)

3. a) Volume = 25 x 50 x 2 = 2500m^3
Convert density to kg/m^3, 1g/cm^3 = 1000kg/m^3
mass = 2500 x 1000 = 2.5e5kg

b) I just did m^3 into liters, so 2500m^3 = 2.5e5liters
2.5e5/8
=312500min approx 217 days

I know its basic question, with unit conversation etc, but I have no answers to check my working. Thanks

Last edited:

Staff Emeritus
Gold Member
Welcome to PF bentleyq!

1. An olympic pool is 50m long 25m wide and a minimum average depth of 2m
a) If the pool is filled as specified, what is the mass of water? Denisty of water to be 1.0g/cm^3
b) How long will it take to fill the pool from a standard garden hose, if the flow rate from hose has average of 8 liters per minute?

2. Homework Equations (density = mass/volume)(volume = LxWxH)

3. a) Volume = 25 x 50 x 2 = 2500m^3
Convert density to kg/m^3, 1g/cm^3 = 1000kg/m^3
mass = 2500 x 1000 = 2.5e5kg

b) I just did m^3 into liters, so 2500m^3 = 2.5e5liters
2.5e5/8
=312500min approx 217 days

I know its basic question, with unit conversation etc, but I have no answers to check my working. Thanks

Check your arithmetic. 2500 * 1000 = 2.5e6. You're too low by a factor of 10.

Your conversion to litres is also similarly wrong.

bentleyq
Ah thanks, i should be 2.5e6liters also, but seems i still have the correct time of 312500min?

Staff Emeritus