a machine has an efficiency of 80%. how much work must be done on the machine so to make it do 50,000 j of…

a machine 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?\n12,500 j\n40,000 j\n62,500 j\n90,000 j

a machine 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?\n12,500 j\n40,000 j\n62,500 j\n90,000 j

Answer

Answer:

C. 62,500 J

Explanation:

Step1: Recall efficiency formula

$\text{Efficiency}=\frac{\text{Output Work}}{\text{Input Work}}$

Step2: Rearrange formula for input work

$\text{Input Work}=\frac{\text{Output Work}}{\text{Efficiency}}$

Step3: Substitute given values

Given $\text{Output Work} = 50000\ J$ and $\text{Efficiency}=0.8$ (since 80% = 0.8), then $\text{Input Work}=\frac{50000}{0.8}=62500\ J$