Answer:
Ei = 40J
Step-by-step explanation:
Given the following data;
Efficiency = 50%
Energy output, Eo = 20 J
To find the amount of energy used by the mixer:
Efficiency = Eo/Ei * 100
Where;
Eo is the output energy.
Ei is the input energy.
Substituting into the formula, we have;
50 = 20/Ei * 100
Cross-multiplying, we have;
50Ei = 2000
Ei = 2000/50
Ei = 40J