## 4A.3 part c

Chris Tai 1B
Posts: 102
Joined: Sat Aug 24, 2019 12:16 am

### 4A.3 part c

Air in a bicycle pump is compressed by pushing in the handle. The inner diameter of the pump is 3.0 cm and the pump is depressed 20. cm with a pressure of 2.00 atm. (c) What is the change in internal energy of the system?

How do we approach part c with the information given? I thought since heat wasn't involved, deltaU = W = 28J, but the answer key says 8J

Dina 2k
Posts: 57
Joined: Wed Sep 18, 2019 12:17 am

### Re: 4A.3 part c

the change in internal energy is from doing work so essentially Δv=w=28J. my solution manual also agrees with 28J.

Anthony Hatashita 4H
Posts: 103
Joined: Wed Sep 18, 2019 12:21 am

### Re: 4A.3 part c

My solution manual says 28J, so I think you may have misread something.

Hailey Kim 4G
Posts: 110
Joined: Sat Jul 20, 2019 12:16 am

### Re: 4A.3 part c

The change in internal energy is equal to the work (which was calculated in part A) in absence of other changes. My solution manual also said the answer was 28 J.

Norman Dis4C
Posts: 101
Joined: Sat Sep 28, 2019 12:16 am

### Re: 4A.3 part c

Mine says 8 as well, but it is not the latest edition, so 28 should be the right answer.