Exercitiul 2, va rog muult!!

Răspuns:
20kJ
Explicație: ΔU=νCvΔT=3/2νRΔT=3/2L⇒L=2ΔU/3=20kJ
ΔU=υCvΔT
L=υRΔT
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ΔU/L=υCvΔT/υRΔT<=>ΔU/L=Cv/R=>L=RΔU/Cv=30R/3R/2=30*2/3=10*2=20 kJ
L=20 kJ