Power and efficiency

• Explain how mechanical processes become inefficient and wasteful when they cause temperature increases, leading to thermal energy dissipation.
• Define power as the specific rate of energy transfer and illustrate this concept using practical examples.
• Calculate power by relating work done to the time taken.

$P = \frac{E}{t}$

• Understand the equivalency between one watt and a transfer rate of one joule per second.
• Calculate system efficiency by determining the ratio of useful energy transferred to the total energy supplied.

$\text{Efficiency} = \frac{\text{Useful energy transferred}}{\text{Total energy supplied}}$