Efficiency Physics Example 1

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Example 1

easy

A machine uses

500 \text{ J}

of input energy and produces

350 \text{ J}

of useful output. What is its efficiency?

Solution

1
Use the efficiency formula: $\eta = \frac{\text{useful output}}{\text{total input}} \times 100\%$ .
2
Substitute the given values: $\eta = \frac{350}{500} \times 100\%$ .
3
$\eta = 70\%$

Answer

\eta = 70\%

Efficiency measures how well a machine converts input energy into useful output. No real machine is 100% efficient because some energy is always lost to heat, sound, or friction.

About Efficiency

The ratio of useful output energy (or power) to total input energy, expressed as a percentage — always less than 100% due to energy losses.

Learn more about Efficiency →

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Energy Work Power