Is ouptut work always less then inpuy work?

Efficiency is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work). The output work is always less than the input work because some of the input work is used to overcome friction. An ideal machine would be 100 percent efficient. All of the input work would be converted to output work. Actual machines lose some input work to friction. You can calculate the efficiency of a machine by dividing the machine's output work by its input work and multiplying that number by 100.

answer:

a=9

step-by-step explanation: lmk if you need a explanation