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Mass/Density problem - please check my working.

  • Thread starter bentleyq
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  • #1
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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:

Answers and Replies

  • #2
cepheid
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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.
 
  • #3
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Ah thanks, i should be 2.5e6liters also, but seems i still have the correct time of 312500min???
 
  • #4
cepheid
Staff Emeritus
Science Advisor
Gold Member
5,192
35
Ah thanks, i should be 2.5e6liters also, but seems i still have the correct time of 312500min???
Looks okay to me! EDIT: your answer for the time, I mean.
 

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