Types of energy and energy efficiency.

Question 1

Which of these can happen to energy?
Destroyed
Converted
Created

Answer 1

Energy can only be converted into another form. It cannot ever be created or destroyed. This is called conservation of energy.

Question 2

What type of energy is also called movement?

Answer 2

Kinetic is the scientific name for movement energy.

Question 3

Which type of appliance would convert electrical energy into sound energy?

Answer 3

A speaker converts electrical energy into sound energy which we can then hear.

Question 4

What type of diagram is used to show energy efficiency?

Answer 4

A Sankey diagram uses specifically sized arrows to show efficiency of energy transfer.

Question 5

How do we calculate percentage efficiency?

Answer 5

Percentage efficiency is calculated by: (useful energy out ÷ total energy in) × 100.

Question 6

Which arrow is bigger in a Sankey diagram for a filament lamp?

Answer 6

In Sankey diagrams of filaments lamps the arrow for heat energy is bigger showing their inefficiency.

Question 7

What are the units for energy?

Answer 7

The units for all types of energy are joules.

Question 8

What is the main useful energy transfer that happens in cars?

Answer 8

The main useful type of energy transfer that happens in cars is chemical (in the fuel) to kinetic to turn the wheels

Question 9

What energy transfer happens in many musical instruments?

Answer 9

Many musical instruments convert kinetic energy to sound energy. This happens in all string and wind instruments.

Question 10

What is the main type of energy transfer in a catapult?

Answer 10

The main type of energy transfer in a catapult is elastic potential to kinetic. This occurs when the catapult is released.