Question

A machine used 20 J of energy to make a

bicycle start. However, 6 J of energy was
wasted as heat. What is the percentage
efficiency of the machine?
a 30%
b 75%
C 70%
d 60%​

Answer 1

a. 30%

Step-by-step explanation:

Given the following data;

Energy as effort, Ee = 20 J

Energy as heat, Eh = 6 J

To find the percentage efficiency (P.E);

P.E = Eh/Ee * 100

Substituting into the formula, we have;

P.E = 6/20 * 100

P.E = 6 * 5

P.E = 30 %

Therefore, the percentage efficiency of the machine is 30 %.