Question

The internal energy of a system in a theoretical process is increased by 45 J and the quantity of
work the system does on its surroundings is 83.7 J. (a) What is the value of q? (b) Is heat
absorbed or given off by the system?

Answer 1

If you are given the internal energy, \(U\) of a system, and work, \(w\) you can find heat, \(q\) by rearranging the formula that relates all of these: \(\sf \color{red}{U = q + w}\)

Remember the rules from algebra? Solve for \(\sf \color{red}{q}\)

Answer 2

Yes. so U=45 right? then w=83.7?

Answer 3

Yessir.

Answer 4

but i made the W negative and the U stays positive? is that correct?

Answer 5

cause there is a table for sign conventions for work and heat? is this right?

Answer 6

work done on the system is postive, while work being applied to the system is negative.

Answer 7

So, is that correct? Me making the w, -w?

Answer 8

Just to clarify, work done on the system is endothermic, absorbed right?