A gas engine working on the constant-volume cycle gave the following results during a one- hour test run: Cylinder diameter: 24 cm, Stroke: 48 cm, Torque: 770 Nm, Mep: 7.5 bar, Average speed: 220 rpm, Average explosion per minute: 77 (= n*K), Gas consumption: 8 kg/h, Lower heating value: 43 MJ/kgfuel, Inlet and outlet temperature of cooling water: 25 C and 60 C respectively, Cooling water used: 600 kg Water specific heat: 4.18 kJ/kg K. Determine: 1) The mechanical efficiency, 2) Indicated thermal efficiency, 3) Draw up a heat balance for the engine on minute basis - MJ/min- (Qf, Qe, Qw).