1. Forces and Energy We have studied FORCES and Newton’s laws.
Forces can be classified into 4 groups
There are 4 Universal Forces
Electricity
Magnetism
Strong Nuclear Force
Weak Nuclear Force
Chemical changes involve electro – magnetic forces b/c they rely on electric charges of atoms and their parts.
Strong nuclear force holds protons and neutron together in nucleus. Stronger than repulsive forces of protons for each other.
Weak = short range attraction of subatomic particles for each other.

2. Energy is the ability to do work
Energy is transferred when a force moves and object through a distance
“Work is the transfer of energy” Both can be measured in joules (Newton-meter)
NOTE: Work is the force on an object over a distance

3. We are going to turn now to a study of energy …
We are going to turn now to a study of energy ….how those forces can be put to work.

4. Energy - the ability to do work. 15.1
Kinetic Energy – energy of motion
Kinetic Energy = ½ mv2
Potential Energy – stored energy
Potential energy = mgh
Gravitational Potential Energy
Elastic Potential Energy
Energy is transferred by a force moving an object through a distance.
Work is the transfer of energy.
Joules = 1 newton-meter
Joules (J) The work done by a force of one Newton traveling through a distance of one meter
Elastic PE – can be compressed or stretched and return to original shape.

5. Forms of Energy
Mechanical Energy – sum of potential and kinetic energy (ex. Speeding train)
Thermal Energy – sum of PE and KE of all the particles in an object. Faster motion - >Thermal E
Chemical Energy – chemical bonds that hold together chemical compounds.
Electrical Energy – transfer of electrons (Batteries)
Electromagnetic Energy – energy that travels through space as waves (ex. Sun light or x-rays)
Nuclear Energy – energy that holds the nucleus together. Released in nuclear fission.

6. Forms of Energy Mechanical Energy – sum of potential and kinetic energy (ex. Speeding train)

7. Forms of Energy Thermal Energy – sum of PE and KE of all the particles in an object.

8. Types of Energy Chemical Energy – chemical bonds that hold together chemical compounds.

9. Types of Energy Electrical Energy – transfer of electrons

10. Forms of Energy Electromagnetic Energy – energy that travels through space as waves

11. Electromagnetic Waves

12. Forms of Energy Nuclear Energy – energy that holds the nucleus together. Released in nuclear fission.

13. Energy Conversion and Conservation 15.2
Law of Conservation of Energy – energy can not be created or destroyed (just change forms)

14. Energy Conversion and Conservation 15.2
Energy Conversion – from one form to another.
Ex. Lighting a match
chemical  thermal  chemical
Ex. Hydroelectric power plant
Gravitational Potential energy kinetic energy  electrical energy
Conservation of Mechanical Energy
(KE + PE) beginning = (KE + PE) end

15. What are energy conversions in picture of pole vaulter

16. Disc Streaming Physics of Fun
Link to real player

17. Energy Conversion and Conservation 15.2
Einstein’s equation, E = mc2, says that Energy and Mass are equivalent and can be converted into each other.

18. Energy Resources 15.3 Nonrenewable Energy Resources
Oil, natural gas, coal, and Uranium.
Renewable Energy Resources
Hydroelectric energy, solar, geothermal, biomass, hydrogen fuel cell
Conserving Energy Resources

19. Integrated Science
SOURCES OF ENERGY

20. Renewable vs. Non-Renewable
Hydroelectric
Solar
Geo-Thermal
Wind
Hydrogen
Ocean Thermal Energy Conversion
Biomass
Coal
Petroleum
Natural Gas
Uranium

21. Non-Renewable Sources
Are available in limited quantities
Are not evenly distributed throughout the world
Cannot be easily replaced (takes million of years)

22. Coal Large deposits in the USA
Burns “dirty”, adding sulfur oxides and nitrogen oxides to the air as well as C02.
Contributes to global warming, air pollution and acid rain

23. Petroleum
We do not have enough to meet our needs in the USA, so must import from unfriendly nations
Produces air pollution and contributes to global warming

24. Natural Gas Burns cleaner than other fossil fuels
Still produces carbon dioxide and contributes to global warming
Not always easy to get to in the ground

25. Offshore Natural Gas Rig

26. Uranium Open pit mines damage environment
Leftover dust is radioactive waste
Rare and only found in a few countries, such as Canada, Kazakhstan and Australia

27. RENEWABLE RESOURCES:

28. Hydroelectric Almost no pollution Lakes can be used for recreation
Expensive to construct
Limited sites
People and wildlife displaced and ecosystems damaged

29. Solar No pollution except in manufacture and transportation of panels
Quiet
Can be used in remote locations
High cost of panels and installation
Only works when sunny

30. Geo-Thermal Mainly used to heat homes in USA Clean
Some electricity needed to pump water through system
Expensive to install
Requires land so not good where population is dense

31. Wind Available world-wide Clean Noisy and some do not like view
Only works when wind blows
Energy must be transported to grid by wires

32. Biomass Made from plants or animals Can be a way to utilize waste
Produces pollution and contributes to global warming
Can be made with domestic resources