Respuesta :
Answer:
X= 700 Joules
Explanation:
The question asked about the efficiency of the work done.
The formula for efficiency is: Efficiency = (Useful output / input work) * 100%
The useful output given in the question is 140J, the question asked for input work. Let X be the input work. It is also given that the efficiency is 20%.
Using the formula of efficiency,
20 = (140/X) * 100
So, we simply solve the above equation.
X= 140*100/20
X= 700 Joules
Answer:
The input work = 700 Joules
Explanation:
Given Data:
Efficiency = 20%
Output work = 140 joules
Input work = ?
The input work done can be calculated using the efficiency formula;
Efficiency = output work done/input work done * 100
Substituting, we have
20 = 140/Input work * 100
20 = 14000/input work
20*input work = 14000
input work = 14000/20
= 700 joules