If a system expands in volume by an amount V (m 3 ) against a constant restraining

If a system expands in volume by an amount ΔV (m³) against a constant restraining pressure P(N/m²), a quantity PΔV(J) of energy is transferred as expansion work from the system to its surroundings. Suppose that the following four conditions are satisfied for a closed system: (a) the system expands against a constant pressure (so that ΔP = 0); (b) ΔE_k = 0: (c) ΔE_p = 0: and (d) the only work done by or on the system is expansion work. Prove that under these conditions, the energy balance simplifies to Q = ΔH.