1.1.14 Efficiency

• Efficiency is the ratio of the useful energy output from a system to its total energy input.
• If a system has high efficiency, most of the energy transferred is useful.
• If a system has low efficiency, most of the energy transferred is wasted.
• Efficiency can be represented as a decimal or as a percentage.
• efficiency space equals space fraction numerator useful space output space energy space transfer over denominator total space input space energy space transfer end fraction.
• efficiency space equals fraction numerator space useful space power space output over denominator total space power space input end fraction.
• Power can also be used to calculate efficiency.