## Chapter 8 HMWK Problem 8.21 Clarification

$\Delta U=q+w$

Sunny Chera 1N
Posts: 20
Joined: Wed Sep 21, 2016 2:56 pm

### Chapter 8 HMWK Problem 8.21 Clarification

The question is stated as follows:

Question: A piece of copper of mass 20.0 g at 100.0 degrees Celsius is placed in a vessel of negligible heat capacity but containing 50.7 g of water at 22.0 degrees Celsius. Calculate the final temperature of the water. Assume that no energy is lost to the surroundings.

Problem: I know that the heat lost by the metal is equal to the heat gained by the water. Therefore, I said that -q=qH20. Although I got the same answer as in the solutions manual, it stated that the heat lost by the metal is equal to the negative heat gained by water (qmetal=-qH20). Is either interpretation considered valid, or is there a flaw with my reasoning? I've had the same issue with several other problems as well.

Theresa_Trieu_2G
Posts: 21
Joined: Wed Sep 21, 2016 2:57 pm

### Re: Chapter 8 HMWK Problem 8.21 Clarification

Either interpretation is valid in this case.