A mass of 15 kg of air in a pistoncylinder device is heated from 25 to 77°C

Question:

A mass of 15 kg of air in a piston€“cylinder device is heated from 25 to 77°C by passing current through a resistance heater inside the cylinder. The pressure inside the cylinder is held constant at 300 kPa during the process, and a heat loss of 60 kJ occurs. Determine the electric energy supplied, in kWh.

A mass of 15 kg of air in a piston€“cylinder