Another Related Rates problem
A certain quantity of gas occupies a volume of 20cm^3 at a pressure of 1 atmosphere. The gas expans wihtout the addition of heat, ,so, for some constant k, its pressure, P, and volume, V, satisfy the relation
(a) Find the rate of change of pressure with volume. Give units.
(b) The volume is increasing at 2 cm^3/min when the volume is 30 cm^3. At that moment, is the pressure increasing or decreasing? How fast? Give units.
The thing that confuses me about this problem is that it says the gas occupies a volume of 20cm^3 at a pressure of 1 atmosphere. I didn't use this information when I worked the problem. Could this information not be needed, or did I screw up somewhere?
Anyways, here is my work:
decreasing at approximately 0.000798 atm/min