Question

What is the change in the internal energy of a system that does 400 joules of work and absorbs 700 joules of heat?

Answer 1

300 J

Step-by-step explanation:

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Answer 2

When a system uses up 400 J (or does 400 J of work), this means the internal energy decreases by 400 J. When it absorbs 700 J of heat, it means 700 J is added to total internal energy present.

Thus, we have a total change of -400 + 700 = 300 J in the internal energy of the system.

Answer: 300 J