An automobile with an internal combustion engine converts the potential energy of gasoline (44 MJ/kg) into the kinetic energy of the moving pistons. If the average internal combustion engine is 10 percent efficient and 1 kg of gasoline is combusted, how much potential energy is converted into energy to run the pistons.
The potetial energy of gasoline is 44 MJ/kg. We are combusting 1 kg of gasoline. So:
Theoretical Potential energy = 44 MJ/kg * 1 kg
Theoretical Potential energy = 44 MJ
If we consider that the engine has an efficiency of 10 %.
Potential Energy Converted = Theoretical Potential Energy * Efficiency/100
Potential Energy Converted = 44 MJ * 10/100
Potential Energy Converted = 4.4 MJ
Answer: 4.4 MJ of Potential Energy are converted into kinetic energy of to run the pistons.