The athlete is doing work because he prevents the weight from falling downward
Answer: False
Explanation:
It's received in elliptical cavities.
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%.