1.] According to the first law of thermodynamics, if work is done on a system, t
ID: 1293823 • Letter: 1
Question
1.] According to the first law of thermodynamics, if work is done on a system, then
a.) heat must be transferred to the system
b.) heat must be transferred from the system
c.) the internal energy of the system must change
d.) the internal energy of the system may change and/or heat may be transferred from the system
2.]Take temperatures and efficiencies to be exact. A heat engine with a thermal efficiency of 40% does 1000J of net work each cycle. How much heat per cycle is lost to the low-temperature reservoir?
Explanation / Answer
1)
d.) the internal energy of the system may change and/or heat may be transferred from the system
2)
efficiency = workdone/heat obsorbed
40% = workdone/heat obsorbed
0.4 = workdone/heat obsorbed
workdone = 0.4*heat obsorbed
= 0.4*1000
= 400 J
heat energy given to the cold resorvoir = 1000 - 400
= 600 J
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.