Mass/Density problem - please check my working.

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Homework Help Overview

The problem involves calculating the mass of water in an Olympic-sized swimming pool and determining the time required to fill the pool using a garden hose. The subject area includes concepts of density, volume, and unit conversions.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to calculate the volume of the pool and subsequently the mass of water using the density of water. They also explore the conversion of volume from cubic meters to liters and calculate the time to fill the pool based on the flow rate of the hose.

Discussion Status

Some participants question the arithmetic in the original poster's calculations, particularly regarding the mass and volume conversions. There is an acknowledgment of potential errors, but the time calculation remains a point of contention with differing opinions on its accuracy.

Contextual Notes

The discussion includes a focus on unit conversions and arithmetic accuracy, with participants reflecting on the implications of these calculations without reaching a definitive resolution.

bentleyq
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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:
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Welcome to PF bentleyq!

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