A machine can never be 100% efficient because some work is always lost due to the lack of materials or equipment that would convert work by 100%. It follows the second law of entropy. The ideal engine is known as Carnot’s engine having a 100% efficiency. So far, no engine has ever gotten to 100%.
Answer:
Friction
Explanation:
Ik cuz i took tha test, i wouldn't lie to fellow students <3