Page 1 of 1

7th edition 4A.3

Posted: Sun Feb 03, 2019 12:05 am
by Alyssa Bryan 3F
Air in a bicycle pump is compressed by pushing in the handle. The inner diameter of the pump if 3.0 cm and the pump is depressed 20. cm with a pressure of 2.00 atm. (a) how much work is done in the compression? (b) is the work positive or negative with respect to the air in the pump? (c) what is the change in internal energy of the system?
I was able to answer parts a and b of the question but seem to not be able to figure out part c. How do I go about solving part c?

Re: 7th edition 4A.3

Posted: Sun Feb 03, 2019 9:21 am
by Jane Burgan 1C
The change in internal energy is equal to q + w. In this problem, q is 0 because there's no heat given off or absorbed as energy, so the change in internal energy is just equal to w. From parts a and b, you know the work value so the change in internal energy will be equal to the work value you solved!