1. Energy and Its Forms
Describe the relationship between work and energy.
Relate kinetic energy to mass and speed.
Analyze how potential energy is related to an object’s position and give examples of gravitational and elastic potential energy.
Give examples of the major forms of energy and explain how each is produced.

2. In an avalanche, a mass of loose snow, soil, or rock suddenly gives way and slides down the side of a mountain.
The avalanche releases a great amount of energy.

3. Energy and Work
Work is done when a force moves an object through a distance.
Energy is the ability to do work.
Energy is transferred by a force moving an object through a distance.
Work is a transfer of energy.

4. Energy and Work Energy has different forms.
The sun gives off energy in the form of heat and light.
Plants convert sunlight into food.
People convert food energy into muscle movement.

5. Many forms of energy can be classified into two general types:
Kinetic Energy
Potential Energy

6. The energy of motion is called kinetic energy.
The kinetic energy of any moving object depends upon its mass and speed.

7. Potential Energy Gravitational potential energy
Potential energy is energy that is stored as a result of position or shape.
Two forms of potential energy are:
Gravitational potential energy
Elastic potential energy

8. Gravitational Potential Energy
Potential energy that depends upon an object’s height is called gravitational potential energy.
An object’s gravitational potential energy depends on its mass, its height, and the acceleration due to gravity.
This type of potential energy increases when an object is raised to a higher level.

9. Potential Energy
This diver has gravitational potential energy as she stands at the end of a diving board.
She gained the potential energy by doing work—by climbing up the steps to the diving board.

10. Gravitational Potential Energy
Place two items at different heights…WHICH DO YOU THINK HAS MORE POTENTIAL ENERGY? WHY?
Gravitational PE depends on an objects height. GPE increases when an object is raised to a higher level.
GPE depends on the mass of something, its height, and the acceleration due to gravity (g).

11. Potential Energy
When this musician pulls the string of her cello to one side, the string is stretched and gains potential energy.

12. Elastic Potential Energy
The potential energy of an object that is stretched or compressed is known as elastic potential energy.
EX: springs, guitar strings,
bike shocks

13. Elastic Potential Energy
The musician adds energy to the cello string by plucking it.
The energy stored in the stretched string is potential energy.
The stored energy is converted into kinetic energy when the string is released and it vibrates.

14. How are work and energy related?
Assessment Questions
How are work and energy related?
Energy is the rate of doing work.
Work is a form of energy.
Work is the transfer of energy.
Energy is created by work.

15. How are work and energy related?
Assessment Questions
How are work and energy related?
Energy is the rate of doing work.
Work is a form of energy.
Work is the transfer of energy.
Energy is created by work. ANS: C

16. 2. Which of these is an example of elastic potential energy?
Assessment Questions
2. Which of these is an example of elastic potential energy?
a bow prepared to release an arrow
a rubber ball thrown into the air
a book about to fall from a table
a truck pulling a trailer

17. 2. Which of these is an example of elastic potential energy?
Assessment Questions
2. Which of these is an example of elastic potential energy?
a bow prepared to release an arrow
a rubber ball thrown into the air
a book about to fall from a table
a truck pulling a trailer ANS: A

18. Assessment Questions
3. A small airplane and a helicopter have identical masses. If the airplane’s altitude compared to the ground is three times that of the helicopter, how much more gravitational potential energy does the airplane have than the helicopter?
0.333 times as much
3 times as much
6 times as much
9 times as much

19. Assessment Questions
3. A small airplane and a helicopter have identical masses. If the airplane’s altitude compared to the ground is three times that of the helicopter, how much more gravitational potential energy does the airplane have than the helicopter?
0.333 times as much
3 times as much
6 times as much
9 times as much ANS: B

20. Forms of Energy
All energy can be considered to be one of three forms:
Kinetic energy, Potential energy, and
energy in fields such as those produced by electromagnetic waves.
Each of these forms of energy can be converted into other forms of energy.

21. Mechanical Electromagnetic Electrical
Forms OF ENERGY
Mechanical Electromagnetic Electrical
Chemical
Thermal
Nuclear

22. What is Mechanical Energy?
Energy due to a object’s motion (kinetic) or position (potential).
The bowling ball has mechanical energy.
When the ball strikes the pins, mechanical energy is transferred to the pins!

23. Examples of Mechanical Energy

24. Mechanical Energy Not limited to machines.
Mechanical energy is the sum of an object’s PE and KE.

25. What is Thermal Energy? Thermal energy = Heat energy
The heat energy of an object determines how active its atoms are.
A hot object is one whose atoms and molecules are excited and show rapid movement.
A cooler object's molecules and atoms will show less movement.

26. What is Chemical Energy?
Energy that is available for release from chemical reactions.
The chemical bonds in a matchstick store energy that is transformed into thermal energy when the match is struck.

27. Examples of Chemical Energy
When bonds are broken, the released energy can do work. All chemical compounds, including fuels such as coal and gasoline, store energy.

28. Forms of Energy
This family is using the chemical energy of burning wood to produce thermal energy for heating marshmallows.

29. What is Electrical Energy?
Energy associated with electric charges.
Easily transported through power lines and converted into other forms of energy

30. What is Electromagnetic Energy?
Light energy or energy that travels through space in the form of waves.
Includes energy from gamma rays, xrays, ultraviolet rays, visible light, infrared rays, microwave and radio bands

31. Lightning bolts transfer electric charge.
Forms of Energy
Lightning bolts transfer electric charge.
Galaxies are giant structures in space that typically contain billions of stars. The stars give off enormous amounts of electromagnetic energy.

32. The energy stored in atomic nuclei is known as nuclear energy.
The nucleus of an atom is held together by strong and weak nuclear forces, which can store an enormous amount of potential energy.
The energy stored in atomic nuclei is known as nuclear energy.
Nuclear fission releases energy by splitting nuclei apart.
Nuclear fusion releases energy when less massive nuclei combine to form a more massive nucleus.

33. Assessment Questions
1. The energy stored in the bonds between atoms of a compound is called
electromagnetic energy.
chemical energy.
atomic energy.
thermal energy.

34. The energy stored in the bonds between atoms of a compound is called
Assessment Questions
The energy stored in the bonds between atoms of a compound is called
electromagnetic energy.
chemical energy.
atomic energy.
thermal energy. ANS: B

35. QUIZ TIME! What type of energy cooks food in a microwave oven?
ELECTROMAGNETIC ENERGY
What type of energy is the spinning plate inside of a microwave oven?
MECHANICAL ENERGY

36. QUIZ TIME!
What energy transformation occurs when an electric lamp is turned on?
ELECTRICAL ENERGY 
ELECTROMAGNETIC ENERGY

37. Electrical energy is transported to your house through power lines.
QUIZ TIME!
Electrical energy is transported to your house through power lines.
When you plug an electric fan to a power outlet, electrical energy is transform into what type of energy?
MECHANICAL ENERGY

38. What types of energy are shown below?
Mechanical and Thermal Energy
(Don’t forget friction)

39. What types of energy are shown below?
Electrical, Mechanical and
Electromagnetic Energy

40. What type of energy is shown below?
Chemical Energy

41. What type of energy is shown below?
Thermal Energy

42. Draw a diagram showing the flow of energy transformations in a car from starting the vehicle to driving. You should have 5 different types of energy.

43. Energy Transfer Sound (mechanical) Electrical Thermal Mechanical
Chemical
Electrical
Light
(Electromagnetic)

44. Tomorrow… How do you know what you know?

45. Kinetic Energy K.E. = m x v2 2 Energy of motion.
Kinetic energy of a moving object depends upon its mass and its speed.
K.E. = m x v2 2

46. Potential Energy G.P.E = Wt. x Ht.
Energy due to position or stored energy.
Gravitational Potential Energy (G.P.E)
G.P.E = Wt. x Ht.

47. Law of Conservation of Energy
Energy is never created or destroyed.
Energy can be converted from one form to another but the total energy remains constant.