A gas absorbs 500 J of heat and does 100 J of work on its surroundings. What is the change in its internal energy?
Answer and explanation
Correct answer: B. 400 J
- Step 1: First law: with the work done by the gas.
- Step 2: J.
Answer
400 J.
Why not the others: 600 J: the work is added instead of subtracted. -400 J: the sign of the result is reversed. 500 J: the work done is ignored.
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