SOLUTION: I need some help with solving direct and indirect variations. The problem I have is how to set them up. The problem is: The volume of gas at a constant temperature varies invers

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Question 190428: I need some help with solving direct and indirect variations.
The problem I have is how to set them up.
The problem is:
The volume of gas at a constant temperature varies inversely as the pressure. Find the volume of a gas under pressure of 24 pound per cubic centimeter if the gas occupies a volume of 123 cubic centimeters under a pressure of 20 pounds per cubic centimeter.
I know i need to use the formula
Q=k/m but I am not quite sure what goes where.
Thanks in advance for any help.

Found 2 solutions by stanbon, Earlsdon:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
The volume of gas at a constant temperature varies inversely as the pressure. Find the volume of a gas under pressure of 24 pound per cubic centimeter if the gas occupies a volume of 123 cubic centimeters under a pressure of 20 pounds per cubic centimeter.
I know i need to use the formula
Q=k/m but I am not quite sure what goes where.
-------------------------------------
Volume = k/pressure
---
1st: solve for "k":
123 = k/20
k = 2460
------------
So the equation is Vol = 2460/pressure
------------------------------------------
Find the volume of a gas under pressure of 24 pound per cubic centimeter
Vol = 2460/24
Volume = 102.5 cc
========================
Cheers,
Stan H.

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Ok, you've got the formula in which Q = volume and m = pressure, and k, of course, is the constant of variation.
You are given that a volume of gas under a pressure (m) of 20 pounds per cu.cm occupies a volume (Q) of 123 cu.cm of gas. Using these values, you can find the value of k in the formula:
Q+=+k%2Fm Substitute Q = 123 and m = 20.
123+=+k%2F20 so that...
k+=+20%28123%29
k+=+2460 Now the formula looks like this:
Q+=+2460%2Fm Substitute m = 24 pounds per cu.cm. to find the volume Q.
Q+=+2460%2F24
highlight%28Q+=+102.5%29cu.cm.