What happens to the change in internal energy of a gas during (b) adiabatic expansion expansion?

What happens to the change in internal energy of a gas during (b) adia

1.	What happens to the change in internal energy of a gas during (b) adiabatic expansion expansion?
Answer» SOLUTION :For adiabatic EXPANSION, `DeltaQ=0`. So From first law, `-DeltaU=DeltaW`. During expansion `DeltaW` is positive and hence `DeltaU` must be NEGATIVE. That is, internal ENERGY of a gas decreases during adiabatic expansion.