1. What is Energy?

2. Joke of the Day
Where do you put dirty lab equipment?

3. Answer
The zinc!

4. Energy – The ability to do work or to cause a change.
Kinetic Energy
The energy of motion. A moving object has the most kinetic energy at the point where it moves the fastest.
Potential Energy
Stored energy; the energy an object has due to its position, molecular arrangement, or chemical compostion.

5. Is it kinetic or potential energy
Example
Kinetic
Potential
Blood flowing through the body
A car moving down the street
An apple in a tree
A bug crawling along a sidewalk
A car at a stop sign
An airplane sitting on a runway
A guitar string vibrating
Water in a waterfall

6. Is it kinetic or potential energy
Example
Kinetic
Potential
Blood flowing through the body X
A car moving down the street
An apple in a tree
A bug crawling along a sidewalk
A car at a stop sign
An airplane sitting on a runway
A guitar string vibrating
Water in a waterfall x

7. Types of Potential Energy
1. Chemical Energy – Chemical energy is stored in the bonds of atoms and molecules. Examples: Biomass, Food, petroleum, natural gas, propane and coal.
2. Nuclear Energy – the energy stored in the nucleus of an atom. It is the energy that holds the nucleus together. Example: The radioactive decay of the nucleus of a uranium atom.

8. Types of Potential Energy (cont.)
3. Gravitational Energy – the energy of place or position. Example: Water that is held in a reservoir behind a hydropower dam has gravitational potential energy. 4. Stored Mechanical (elastic) energy – the energy stored in objects or substances by the application of force. Example: Compressed metal springs and stretched rubber bands.

9. Types of Kinetic Energy
1. Radiant (light) energy – is electromagnetic energy that travels in transverse waves. Examples: Visible light, x-rays, gamma rays, radio waves, and solar energy. 2. Thermal (heat) Energy – the internal energy in substances. It is the vibration and movement of atoms and molecules within substances. Example: Geothermal energy.

10. Types of Kinetic Energy (cont.)
3. Mechanical (motion) energy – The movement of objects or substances from one place to another. 4. Sound Energy – Sound is the movement of energy (vibrations) through objects or substances in longitudinal waves. 5. Electrical Energy – the movement of electrons. Example: Lightning and electricity

11. Identify the type and form of energy
Example
Form (s)
Type (s)
(Kinetic or potential)
A running dog
Thermal , Mechanical, Chemical KE
A burning candle
A book on a table
A green plant
Sunlight
A battery
A cup of coffee

12. Identify the type and form of energy
Example
Form (s)
Type (s)
A running dog
Mechanical, Thermal, Chemical
KE, PE
A burning candle
Thermal, Chemical, Light
A book on a table
Gravitational PE
A green plant
Chemical
PE, KE
Sunlight
Radiant, Light, Thermal KE
A battery
Chemical, electrical
A cup of coffee
Thermal, chemical

13. Kinetic Energy Both Moving Energy
Kinetic Energy increases as mass increases
The amount of Kinetic energy is determined by mass and velocity.
Thermal
Mechanical
Electricity
Radiant/Light
Sound
Stored Energy
due to an object’s position and
Chemical composition
Nuclear
Chemical
Elastic (Stored Mechanical)
Gravitational
Both have the ability to cause change.
Kinetic Energy
Potential Energy

14. Class Notes:Calculating Energy
To calculate the kinetic energy of a moving object you must know the mass and velocity. To calculate you use the following formula:
Kinetic energy (KE) = 1 mass x velocity2 2

15. What is the kinetic energy of a 5 kg object moving at 7 m/s?
KE = ½ (mass) x (velocity)2
KE = ½ (5 kg) x (7 m/s)2
KE = 2.5kg x 49 m2/s2
KE = kg●m2 is equal to Joules s2
KE = Joules

16. What is the kinetic energy of a 10 kg object moving at 8 m/s?
KE = ½ (mass) x (velocity)2
KE = ½ (10 kg) x (8m/s)2
KE = 5kg x 64 m2/s2
KE = 320 kg●m2 s2
KE = 320 Joules

17. Calculating Potential Energy
To calculate the potential energy of an object you must know the mass, height, and gravitational velocity (g = 9.8m/s2). To calculate you use the following formula:
GPE = mgh
Gravitational Potential Energy = mass x gravitational velocity x height

18. What is the gravitational potential energy of a diver with a mass of 60 kg who is 10 m above the water?
GPE = mass x gravitational velocity x height
GPE = 60 kg x 9.8 m/s2 x 10 m
GPE = 60 kg x 98 m2/s2
GPE = 5,880 Joules

19. What is the gravitational potential energy of a rock with a mass of 20 kg who is 5 m above the ground?
GPE = mass x gravitational velocity x height
GPE = 20 kg x 9.8 m/s2 x 5 m
GPE = 20 kg x 49 m2/s2
GPE = 980 Joules

20. Energy Transformations
Energy can be transformed from one form to another.
Devices such as light bulbs, hair dryers, and automobile engines convert one form of energy into other forms.
Mechanical energy = Kinetic Energy + Potential Energy

21. How many examples of energy transformations can you fill in the chart below?
Chemical
Electric
Heat
Light
Mechanical
Sound
Battery
Car Running
Television
Stove
Tread Mill
Radio
Fire
Sun, Lava,
Stop Light
Running
Microwave
Echo

22. The Law of Conservation of Energy
According to the law of conservation of energy, energy cannot be created or destroyed (it can only be transformed from one form to another).
Friction converts mechanical energy into thermal energy.
Fission and fusion are nuclear reactions that convert a small amount of mass in a nucleus to an enormous amount of energy

23. How are work and energy created?
When work is done, energy is transferred.

24. Classwork
Complete NTG section 13.1 and 13.2