1. Energy and Energy Resources
Chapter 9
Energy and Energy Resources

2. Kinetic and Potential Energy
9:1

3. Terms Energy- the ability to do work
Unit: joules (J)
Work- involves a transfer of energy and occurs
when a force causes an object to move in the
direction of the force ( work = force x distance)

4. Kinetic Energy energy of motion All moving objects have kinetic energy
Kinetic energy depends on speed and mass
K.E. = m v2 2
K.E. = kinetic energy m = mass v = velocity
faster objects — more kinetic energy
objects with more mass — more kinetic energy

5. Try This
What is the kinetic energy of a turtle with a mass of .9 kg moving at .05 m/s?
2. What is the kinetic energy of a 6,400 kg tractor trailer traveling at 25m/s?

6. Potential Energy
energy an object has because of its position or shape.
Example: stretching a rubber band changes its shape. This gives it elastic potential energy.
Gravitational potential energy- energy an object
has due to its position above the Earth's surface.
Example: lifting up the rubber band gives it G.P.E.
Depends on the height and the weight of an object
G.P.E. = weight x height

8. Mechanical Energy
the total energy of motion and position of an object.
M.E. = P.E. + K.E
M.E. = mechanical energy
P.E. = potential energy
K.E. = kinetic energy
Mechanical Energy can be all potential energy, all kinetic energy or part potential and part kinetic energy

9. Forms of Energy
9:1 continued

10. Thermal Energy
Thermal Energy- total energy of particles that make up an object.
Particles at higher temperatures have more thermal energy(because they are moving faster) than the same number and kind of particles at a lower temperature
Increasing the number of particles you have in an object increases the thermal energy
Mostly kinetic energy
Examples: stove, heater, Atlantic Ocean, curling iron, furnaces, etc.

11. Chemical Energy
Chemical Energy- energy of a compound that changes as its atoms are rearranged to form new compounds
Much potential energy stored in chemical bonds
Potential energy is converted to kinetic energy during the chemical reaction
Examples: food, carbohydrates, gasoline, kerosene, butane, firewood, etc.

12. Electrical Energy Electrical Energy- energy of moving electrons
Mostly kinetic energy
Examples: TV, VCR, flashlight, computer, calculator, & anything electrical or battery operated

13. Sound Energy Sound Energy- caused by vibrations of an object
Potential energy is converted into kinetic energy
Potential energy- example: stretching the string of a guitar
Kinetic energy- the string moving and vibrations occurring in the air
Examples: speakers, singing, musical instruments, sonar, ultrasounds, taping on a desk, etc.

14. Light Energy
Light Energy- produced by the vibrations of electrically charged particles
Mostly kinetic energy
Electromagnetic radiation
Examples: radio waves, visible light, radar, microwaves, infrared radiation, UV rays, x-rays, gamma rays, etc.

15. Nuclear Energy
Nuclear Energy- the energy associated with the changes in the nucleus of an atom (the nuclei split or join together)
Potential energy is converted into kinetic energy
Potential Energy stored in the nucleus of an atom
Kinetic Energy when the nucleus is split (fission) or joins with other nuclei (fusion)
Examples: nuclear fusion in stars and in the sun, nuclear fission at a nuclear power plant, nuclear bombs, some types of radiation therapy, radioactive decay,

16. Energy Conversions
9:2

17. Terms Energy Conversion Energy Efficiency Video Segment
A change from one form of energy into another
Energy Efficiency
A comparison with the amount of energy before a conversion with the amount of useful energy after a conversion
Video Segment

18. From Kinetic to Potential and Back

19. Conversions Involving Chemical Energy