Astudent does 1,000 j of work when she moves to her dormitory. her internal energy is decreased by 3,000 j. determine the heat during this process. does she gain or lose her heat?

-2000 J (heat lost)

Explanation:

We can solve the problem by using the 1st law of thermodynamics:

where

is the change in internal energy of a system

Q is the heat absorbed by the system

W is the work done by the system

In this situation, we have

(work done by the student)

(decrease in internal energy)

So the heat is

And the negative sign means the student has lost heat.