# Conservation of energy (topic 3) Flashcards

What is the formula for energy efficiency?

Useful energy output/total energy input (x 100 for percentage)

HOW to draw Sankey diagrams?

The useful energy follows the main arrow whereas the wasted energy peels of at the side. If required to draw accurately you would need to make the width for e.g. 1 cm = 1 W

What are the different energy stores?

Kinetic, internal (particles), elastic potential, gravitational potential, electrical, magnetic, thermal.

What is the formula for kinetic energy?

KE = 1/2 mass x velocity {2}

IF you double the mass what do you do to the KE?

Double it.

If You Double the velocity what do you do to the KE?

Quadruple it. x4

How do you calculate the change in GPE?

Change in GPE = m x 9.81 x change In vertical height.

what Is the equation for power?

work done/time taken

What is power measured in?

Watts

What is radiation?

energy transferred through waves e.g inferred waves.

What is thermal conductivity?

a measure of how easily thermal energy can be transferred in that material