12. Energy

Question 1

Kinetic Store

Answer 1

Associated with motion

Examples:
1. Rolling soccer ball
2. Spinning frisbee

Question 2

Gravitational Potential Store

Answer 2

Associated with the position (height) of objects relative to a reference level (usually the ground)

Examples:
1. Book above the ground

Question 3

Elastic Potential Store

Answer 3

Associated with objects which are stretched or compressed

Examples:
1. Stretched bow string
2. Compressed string

Question 4

Chemical Potential Store

Answer 4

Associated with the bonds of chemical compounds. Can be released through chemical reactions

Examples:
1. Food
2. Fossil fuels
3. Batteries

Question 5

Internal Store

Answer 5

The total kinetic energy associated with the random motion of the particles and the total potential energy between the particles in the system.

Examples:
1. A hot object, such as a hot metal or a hot drink

Question 6

Nuclear Store

Answer 6

Associated with the energy in the nucleus of an atom

Examples:
1. Nuclei of atoms

Question 7

4 Ways Energy can be Transferred

Answer 7

Energy can be transferred:
1. Mechanically by a force acting over a distance
2. by heating due to a temperature difference
3. by propagation of waves
4. electrically by an electric current

Question 8

Principle of Conservation of Energy

Answer 8

The principle of conservation of energy states the energy can neither be created nor destroyed, but can be transferred from one body to another or converted from one form to another. The total energy in an isolated system is constant.

Question 9

Dissipation

Answer 9

If there is friction and air resistance, energy from the object/force will be dissipated to the surroundings as heat and sound.

Question 10

Power

Definition

Answer 10

Power is the rate of work done or the rate of energy transfer

P = E/t

Question 11

Efficiency

Calculation

Answer 11

useful energy output/total energy input x 100%
or
useful power output/total power input x 100%