Conservation of energy (topic 3)

Question 1

What is the formula for energy efficiency?

Answer 1

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

Question 2

HOW to draw Sankey diagrams?

Answer 2

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

Question 3

What are the different energy stores?

Answer 3

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

Question 4

What is the formula for kinetic energy?

Answer 4

KE = 1/2 mass x velocity {2}

Question 5

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

Answer 5

Double it.

Question 6

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

Answer 6

Quadruple it. x4

Question 7

How do you calculate the change in GPE?

Answer 7

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

Question 8

what Is the equation for power?

Answer 8

work done/time taken

Question 9

What is power measured in?

Answer 9

Watts

Question 10

What is radiation?

Answer 10

energy transferred through waves e.g inferred waves.

Question 11

What is thermal conductivity?

Answer 11

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