Question

You have a machine that tells you exactly how much work in joules is put into a machine and how much work was produced. The readings that you just received from the machine state that the input work was 345 joules and the output work was 330 joules. The law of conservation of energy states that input should equal output. How can you explain the "lost" 15 joules?

Answer 1

The 15 joules of energy that was lost was because of the inefficiency of the machine. The efficiency of the machine is 96% efficient. Therefor the 4% of efficiency that is lacking is the cause for the '15 joules lost'