Why is the efficiency of a machine always less than 100%?

The percentage of the work input that becomes work output is the efficiency of a machine. Because there is always some friction, the efficiency of any machine is always less than 100 percent.

Explanation:

Sub to rockingcoolstyle15 on yt

c because the action was the roller coaster reaches bottom of hill (action) reaction would be blood tends to drain away from head

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