A machine has an efficiency of 15%. If the energy input is 300 joules, how much useful energy is generated?(1 point) Responses 285 joules 285 joules 255 joules 255 joules 45 joules 45 joules 20 joules 20 joules

Answer 1

To calculate the useful energy generated by the machine, you can use the formula for efficiency:

\[ \text{Efficiency} (%) = \left(\frac{\text{Useful Energy Output}}{\text{Energy Input}}\right) \times 100 \]

In this case, the efficiency is 15% and the energy input is 300 joules. Rearranging the formula to find the useful energy output:

\[ \text{Useful Energy Output} = \text{Efficiency} \times \frac{\text{Energy Input}}{100} \]

Substituting the values:

\[ \text{Useful Energy Output} = 15 \times \frac{300}{100} = 15 \times 3 = 45 \text{ joules} \]

So, the useful energy generated is 45 joules.