1. Comprehensive Science 2
Chapter 8
Comprehensive Science 2

2. Lesson 1
Forms of Energy

3. Energy Any way in which we cause change Examples:
Eating before working out
Pushing an object
Pulling an object
Turning a light on
Plants converting sugar to energy

4. Potential Energy Stored energy
The brief moment in which an object has the “potential” to have energy
Examples:
Rock at the top of the hill
Rubber band before it is stretched
Moment before object is let go

5. Gravitational Potential Energy
Anything that has mass and height above earths surface
Dependent on the mass of an object and the distance an object is to earth
Examples:
ANYTHING!!!

6. Chemical energy
Energy that is stored and released through chemical bonds
Examples:
When your body takes food that is eaten and converts it into energy
Batteries
Cracked glow sticks

7. Nuclear Energy Energy stored and released in the nucleus Examples:
Sun setting is nuclear energy because the rays that are reflected is occurring via nuclear fission
When an atom breaks apart
Nuclear fusion
Nuclear fission

8. Kinetic energy Energy of motion Examples: Ball rolling down the hills
Rubber band being let go

9. Kinetic energy of motion
The amount of kinetic energy an object has in relation to speed
For example, If you have two objects and object one weighs 3.5kg and another weighs 5.5kg….. Both have the same speed, however the heavier object has more kinetic energy

10. Electric Energy Any type of energy in an electric current Example:
Copper wire attached to a battery

11. Mechanical Energy
Sum of potential energy and kinetic energy

12. Thermal Energy
Sum of kinetic energy and potential energy

13. Wave A disturbance that transfers energy from one object to another
Examples:
A rock falling in a pond of water
Dominos that knock each other over

14. Sound Energy Energy that is carried through sound waves Examples:
Radio
Earphones
Speakers

15. Radiant energy When energy is carries via electromagnetic waves
Examples:
Light
Different rays emitted by light

16. Activity!!
ENERGY PAMPHLET ACTIVITY

17. Energy Transfers and Transformation
Lesson 2
Energy Transfers and Transformation

18. Law of Conservation of Energy
Energy cannot be created nor destroyed
Energy CAN be transferred and transformed

19. Energy Transfer
Energy moves from one object to another, but does not change form
Tennis ball example:
Tennis player hits ball
Mechanical energy in racket changes movement of the ball
Mechanical energy of the ball increases after it is hit
Write down in your notes another example of Energy Transfer

20. Energy Transformation
When energy is converted to another form of energy
Tennis example:
The mechanical energy in the racket and tennis ball comes from somewhere…
Chemical energy from the tennis player’s muscle TRANSFORMS into mechanical energy

21. Energy and Work Simply put…. Work is energy transferred by force
Example:
Pushing a heavy shopping cart for 10 m
You lift your school bag upwards by 1 m
Work = Force x Distance
Tennis example

22. Inefficiency of Energy Transformations
Anytime an energy transformation or transfer takes place, some energy is transformed into thermal energy
When force is applies or work occurs there is a certain percentage that is lost because it can be converted into sound energy or thermal energy

23. Inefficiency continued
Energy transformations are inefficient because not all energy that is transformed to another form is usable

24. A system that exchanges matter or energy with the environment
Open Systems
A system that exchanges matter or energy with the environment
Write examples in your notes.

25. A system That does not exchange matter or energy with the environment
Closed systems
A system That does not exchange matter or energy with the environment
Can you think of any examples?

26. Renewable resources VS. Nonrenewable resources

27. On your own…
What energy transformations occur in a wind turbine?
Identify an energy transfer and an energy transformation that occur when someone plays guitar.

28. Lesson 3
Particles in Motion

29. Kinetic Molecular Theory
Explains how particles move
1. All matter is made of particles
2. Particles are in constant, random motion
3. Particles constantly collide with each other and with the walls of their container

30. Heat Transfer
Conduction: is the transfer of thermal energy by collisions between particles in matter
a. Example: Thermal energy from the burner is transferred into water by conduction
Radiation: Transfer of thermal energy by electromagnetic wave
a. Example: Thermal energy is transferred out of hot water by radiation and conduction
Convection: transfer of thermal energy by the movement of the particles from on part of a material to another
a. Examples: cycles of rising and sinking water transfer thermal energy throughout water by convection

31. Ending of Ch. 8 Changes between solids and liquids
Melting
Freezing
Changes between liquids and gases
Vaporization
Boiling and evaporation
Changes between solids and gases
Sublimation and deposition
Conductors vs. Insulators