In a closed system, if the internal energy increases, what can be said about the work done and heat added? (2020)
Practice Questions
1 question
Q1
In a closed system, if the internal energy increases, what can be said about the work done and heat added? (2020)
Work done is positive and heat added is negative
Work done is negative and heat added is positive
Both work done and heat added are positive
Both work done and heat added are negative
According to the first law of thermodynamics, if the internal energy increases, it implies that either work is done on the system or heat is added to the system.
Questions & Step-by-step Solutions
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Q
Q: In a closed system, if the internal energy increases, what can be said about the work done and heat added? (2020)
Solution: According to the first law of thermodynamics, if the internal energy increases, it implies that either work is done on the system or heat is added to the system.
Steps: 5
Step 1: Understand that a closed system means no matter can enter or leave the system, but energy can be exchanged.
Step 2: Know that internal energy is the total energy contained within the system.
Step 3: Recall the first law of thermodynamics, which states that the change in internal energy (ΔU) is equal to the heat added to the system (Q) minus the work done by the system (W).
Step 4: If the internal energy increases (ΔU > 0), it means that the sum of heat added to the system and work done on the system is greater than the work done by the system.
Step 5: Conclude that either heat is added to the system (Q > 0) or work is done on the system (W < 0), or both.
