Page 1 of 1

Positive and Negative Signs 8.21

Posted: Wed Jan 24, 2018 12:29 pm
by Ammarah 2H
For questions like 8.21 on the homework, how do we know which side will be positive and which will be negative? Is the one with the lower initial temperature always the negative one?

Re: Positive and Negative Signs 8.21

Posted: Wed Jan 24, 2018 3:13 pm
by SantanaRodriguezDis1G
it doesn't matter which side has the negative. either way it would turn out to be the same answer

Re: Positive and Negative Signs 8.21

Posted: Wed Jan 24, 2018 4:27 pm
by Brigitte Phung 1F
I think it would also help to look at it in terms of the objects themselves. q is positive when heat has been absorbed by the system, whereas q is negative when heat has flowed from the system. Hope this helps!

Re: Positive and Negative Signs 8.21

Posted: Wed Jan 24, 2018 4:55 pm
by Meredith Steinberg 2E
It ends up not mattering which side gets the negative. What's important to know (as seen in the solutions manual) is that
heat lost=-(heat gained).