Understanding Otto Cycle: Calculating Cycles, Heat Input, and Efficiency

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The discussion revolves around calculating various aspects of the Otto cycle for a four-stroke engine delivering 150 hp at 3600 rpm. To determine the number of cycles per minute, it is established that there are 1800 cycles, as the engine completes two cycles per revolution. For calculating heat input, the thermal efficiency of 20% is noted, and the formula E=W/Q is referenced, with the need to find work done using the engine's horsepower. The conversion of horsepower to kilowatts is highlighted, emphasizing that 1 hp equals 0.7457 kW. Understanding these calculations is essential for determining both heat input and wasted heat in the engine's operation.
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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.
 
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For (b), the 150 horse power is the clue.

1 hp = 0.7457 kW

What is the energy delivered in 1 minute.
 

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