A system does 200 J of work and at the same time absorbs 150 J of heat. The magnitude of the change in internal energy is J. (Nearest integer)

Question

A system does 200 J of work and at the same time absorbs 150 J of heat. The magnitude of the change in internal energy is  J. (Nearest integer)

Canvas Classes · Accepted Answer

Strategy:
 Apply the First Law of Thermodynamics () with careful attention to sign conventions for heat absorbed and work done.

Step 1: Identify  and  with signs
- Heat absorbed by system: .
- Work done by system: .

Step 2: Calculate 
.
The magnitude of change is .

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