Two different fuels are being considered for a 1 MW (net output) heat engine which can operate between the highest temperature produced during the burning of the fuel and the atmospheric temperature of 300 K. Fuel A burns at 2500 K, delivering 50 MJ/kg (heating value) and costs $2 per kilogram. Fuel B burns at 1500 K, delivering 40 MJ/kg and costs $1.50 per kilogram. Determine the minimum fuel cost per hour for
(a) Fuel A
(b) Fuel B.