The horsepower rating commonly used for engines indicates the rate at which they can do work. A one-horsepower engine can do 746 J of work each second. A lawn mower has a 6.50 horsepower engine that runs at 3800 rpm. Each revolution of the engine represents one engine cycle.

(a) What amount of work does the engine do on each cycle?

(b) If the hot reservoir of the engine supplies 142 J of heat each cycle, hot much heat must the engine expel to the cold reservoir?