Question

efficiency is the ratio of work output to work input. it is expressed as a percentage (%). the higher the percentage (%), the higher the efficiency of the machine. input work is the amount of work put into a machine. work output is the amount of work done by the machine. friction is the opposing force when objects tend to or are in contact. an ideal machine is 100% efficient, and it loses no work due to friction. ideal machines do not exist.

choose the correct answer
an ideal machine is a machine with 100% efficiency. do ideal machines exist in the real world?
yes
no
we do not know

Explanation:

In the real world, friction is always present when objects interact (like machine parts moving). An ideal machine requires 100% efficiency with no work loss due to friction, but since friction exists in reality, ideal machines can't exist.

Answer:

B. No