# During the expansion of the gas, caused by its heating in a cylinder with a cross section of 100 cm ^ 2

**During the expansion of the gas, caused by its heating in a cylinder with a cross section of 100 cm ^ 2, Q = 0.75 * 10 ^ 5 J P = 1.5 * 10 ^ 7 J was transferred to the gas, how much did U change if the piston moved 40 cm .?**

To find the change in the internal energy of the gas in the cylinder under consideration, we use the formula: ΔU = Q – A ‘= Q – P * ΔV = Q – P * S * h.

Variables: Q – transferred heat energy (Q = 0.75 * 10 ^ 5 J); P is the pressure in the cylinder (P = 1.5 * 10 ^ 7 Pa); S – section of the cylinder (S = 100 cm2 = 10 ^ -2 m2); h – piston movement (h = 40 cm = 0.4 m).

Let’s perform the calculation: ΔU = Q – P * S * h = 0.75 * 10 ^ 5 – 1.5 * 10 ^ 7 * 10-2 * 0.4 = 15 * 10 ^ 3 J.

Answer: The internal energy of the gas in the considered cylinder has increased by 15 kJ.