Practice question

**First law applications** for isobaric W = P ΔV, Q = n C_p ΔT, ΔU = n C_v ΔT, for isothermal ideal gas ΔU=0 Q=W=n R T ln(V₂/V₁), for adiabatic Q=0 W= -ΔU = (P₁V₁ - P₂V₂)/(γ-1), for isochoric W=0 ΔU=Q=n C_v ΔT, enabling calculation of Q,W,ΔU for any process. Δ Q = m s Δ T . m = 0.45 , s = 900 , Δ T = 60 - 30 = 30 . Δ Q = 0.45 × 900 × 30 = 12150 J . Using first law ΔU = Q - W, W = ∫ P dV, isobaric W = P ΔV,