Amachine has an efficiency of 80%. how much work must be done on the machine so to make it do 50,000 j of output work? 12,500 j 40,000 j 62,500 j 90,000 j

62,500 J

Explanation:

The efficiency of a machine is defined as

where

is the output work of the machine

is the work in input

For the machine in this problem, the efficiency is 80 %, so:

We also know that the output work must be

So, we can re-arrange the previous equation to find the input work needed:

i'm on my way to history not a mistory.