Otto Cycle?? Please help ASAP! I have a question that my entire class is confused over. I need help on it for a test, but I have no idea where to go with it. It doesn't seem to fit any of the equations or situations I have been using. The question is: A four-stroke engine runs on the otto cycle. It delivers 150 hp at 3600 rpm. a) how many cycles are there in one minute? I know that this is just 3600/2 = 1800 cycles b) If the thermal efficiency of the engine is 20% what is the heat input per minute? I don't know how to get this one. I know the equation I want is E=W/Q, but I don't know how to find the work done. do I use the 150 hp, 3600 rpm, or combine them somehow? c)How much heat is wasted to the environment / minute. I need the answer to part b I think for this right? Any help at all would be great. Thanks for looking.