Silly math problem (precipitation)

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Homework Help Overview

The discussion revolves around a math problem related to precipitation, specifically calculating the total volume of water from rainfall over a specified area and comparing it to the flow rate of a river. The problem involves understanding unit conversions and volume calculations.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to calculate the volume of water based on rainfall measurements and the area of the city. Some participants question the correct approach to calculating volume, emphasizing the need for proper unit conversions, particularly between square kilometers and square centimeters.

Discussion Status

Participants are actively engaging with the problem, providing guidance on unit conversions and calculations. There is recognition of the importance of consistent units when determining volume, and some clarification on the difference between area and volume calculations has been offered.

Contextual Notes

There are constraints regarding the original poster's understanding of unit conversions and the setup of the problem, which includes specific measurements and flow rates. The discussion highlights the need for clarity in mathematical operations involving different units.

yoshi6
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Hello everyone. I have this simple math problem that is worth 5 marks and I am not sure if it is right. Anyway it is on precipitation, here it is!

Record the amount of water (in centimetres) the tipping bucket rain gauge received. Calculate the total volume of water this would equal if this amount fell over the City of Guelph (area 86km squared). Is this volume greater or less than the average volume of water which flows through the city in the Spped River during a 24 hour period (average flow rate = 5.8mcubed per second).

Okay so first I am having trouble calculating the volume, I don't know why:

my recordings are: the amount of water (in centimetres) is four tenths of an inch--coverted equals 1.01600cm.

so, can I calculate this by multiplying 1.01600 x 86km

THANKS!
 
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oops sorry i just read that i can't posthis here
 
yoshi6 said:
Hello everyone. I have this simple math problem that is worth 5 marks and I am not sure if it is right. Anyway it is on precipitation, here it is!

Record the amount of water (in centimetres) the tipping bucket rain gauge received. Calculate the total volume of water this would equal if this amount fell over the City of Guelph (area 86km squared). Is this volume greater or less than the average volume of water which flows through the city in the Spped River during a 24 hour period (average flow rate = 5.8mcubed per second).

Okay so first I am having trouble calculating the volume, I don't know why:

my recordings are: the amount of water (in centimetres) is four tenths of an inch--coverted equals 1.01600cm.

so, can I calculate this by multiplying 1.01600 x 86km

THANKS!
If I understand this correctly- that there was no "funnel" to channel a lot of water into a small area (some rain guages are built that way to make it easier to read small amounts of water) then saying 1.016 cm fell on the bucket, then 1.016 cm would fall on every "bit" of the city. However, you cannot multiply 1.016 cm by 86 km- in fact there is no "86 km"; the area is 86 square kilometers. Convert 86 square kilometers to square cm Multiplying that by 1.016 cm will give the volume in cubic cm.
Now you are told that the Spped River has a flow of 5.8 cubic meters per second. Convert 24 hours to seconds (there are 60 seconds per minute, 60 minutes per hour) and multiply by 5.8 cubic meters per second to determine the total flow in cubic meters. In order to compare that to the volume in cubic centimeters calculated above, either convert the cubic centimeter volume to cubic meters or vice-versa.
 
THANKYOU! I see now
 
no nevermind, i don't think it is working out properly...hmm
 
no nevermind, i don't think it is working out properly...hmm

Just make sure you use consuistant units whan finding the volume. If you have the area in meters_squared then multiply by the rain depth in meters to get volume in meters_cubed etc.

Also when converting square or cubic units then make sure you use the appropriate power in the conversion. For example 1 m^2 is 100^2 cm^2 (10,000 square_cm) and 1 m^3 is 100^3 cm^3 (1000,000 cubic_cm). Failure to convert units correctly is a common source of error in this type of question.
 

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