The output of an IC engine is measured with a rope-brake dynamometer. The brake-pulley diameter is 750 mm and the rope diameter 50 mm. The dead load on the tight side of the rope is 410 N and the spring-balance reading is 50 N. The engine uses 4 kg/h of fuel at 1000 rpm; the calorific value of the fuel is 44 100 kJ/kg. Calculate (a) the brake specific fuel consumption (in kg/kWh) and (b) the brake thermal efficiency (in %).