2. Energy

3. Nature of Energy  Energy is all around you! You can hear energy as sound You can see energy as light And you can feel it as wind  You use energy when you: hit a softball lift your book bag compress a spring digest your food  All living things depend on energy for growth and movement

5. Energy  Energy: the ability to move or cause change in matter (doing work) expressed in units of joules (J) can be transferred from one object to another Two general types:  Potential  Kinetic

6. Potential Energy (PE) stored energy that an object has due to its position or chemical composition example:  Gravitational potential energy – results from vertical position or height Which soccer ball has more gravitational potential energy? Explain your reasoning. 0.45 kg

7. Kinetic Energy (KE) energy of motion increases as mass or velocity increases Which soccer ball has more kinetic energy? Explain your reasoning. 2 m/s3 m/s 0.45 kg

8. Relationship Between PE and KE PE KE What is happening to the PE and KE as the soccer ball falls to the feet of the mid-fielder?

9. Forms of Energy  Mechanical Mechanical  Sound Sound  Chemical Chemical  Thermal Thermal  Electromagnetic or Radiant Electromagnetic or Radiant  Electrical Electrical  Nuclear Nuclear

10. Mechanical Energy  energy that moves objects  the total energy of motion and position of an object  may be in the form of potential energy and/or kinetic energy  Example: If a student were to lift and/or drop a stack of textbooks, mechanical energy would be involved http://www.columbiastate.edu/HSS-Textbook-Information What are some other examples of mechanical energy?

11. Sound Energy  energy that results from the vibration of particles in a solid, liquid, or gas  can be impacted by temperature and pressure  must have a medium (usually air) to travel through - cannot travel through empty space Medium: a substance through which it can travel This person is listening to someone telling a secret. How are the sound waves being generated?

12. Chemical Energy  type of potential energy stored in the chemical composition of matter  depends on the types and arrangement of atoms in a substance i.e.  A bond between a hydrogen atom and an oxygen (H-O) atom will release more energy than one between two carbon atoms (C-C) What are some examples of chemical energy? C C C C C C H H H H H H H O HO OH Glucose ≈347,000 J ≈464,000 J

13. Thermal (Heat) Energy  results from the movement (kinetic energy) of atoms or molecules in matter  when particles move faster they have more thermal energy than when they move slower  depends on the number of particles in a substance Which box of particles has more thermal energy? Why?

14. Radiant/Electromagnetic Energy  transmitted through space in the form of electromagnetic waves  light, X-rays, radio waves, etc. are representative of electromagnetic energy  can travel through empty space Image taken from: http://zebu.uoregon.edu/~imamura/122/lecture-2/em.htmlhttp://zebu.uoregon.edu/~imamura/122/lecture-2/em.html

15. Electrical Energy  movement of electrons through a conductor. Conductor: a material that can carry electricity (ex. the wiring in homes, lightning)

16. Nuclear Energy  stored in the nucleus of an atom  is released when an atom’s nucleus breaks apart (fission) or when the nuclei of two atoms come together (fusion)  Example: Nuclear fission takes place in a nuclear power plant while nuclear fusion takes place in the Sun. + + + + Deuterium Tritium neutron helium Is nuclear fission or nuclear fusion taking place? Explain your reasoning.

17. Identify the Form of Energy Electromagnetic (radio waves) Chemical (food) Thermal (burner increases movement of H 2 O molecules) Mechanical (moving gears) Electricity (electrical outlet)

18. Forms of Energy (Grouping Activity)  Organize the 21 cardstock sheets into seven groups. Each group should consist of: words representing a form of energy (bold) some descriptions describing the form of energy (bullet) a visual representation of the form of energy.  When you think the sheets are correctly grouped, have me come and confirm whether it is correct.

19. Energy Conversions  a change from one form of energy into another  energy can be converted into any other form and is often converted into more than one form  most of the wasted or unwanted energy in a conversion is attributed to heat (friction)  Example Electromagnetic energy (in the form of light) from the Sun is converted, by plants, into chemical energy in the form of glucose What is an example of an energy conversion you have experienced in your own life? Light Energy CO 2 H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O H2OH2O O2O2 O2O2 O2O2 O2O2 O2O2 O2O2 C 6 H 12 O 6 6CO 2 + H 2 O C 6 H 12 O 6 + 6O 2 light energy

20. Energy Conversions

21. Identify the Energy Conversions The apparatus to the right was placed into a bell jar. What energy conversions take place when it is operating? 1. Chemical energy (in the battery) 2. Electrical Energy (electricity moving through the wires) 3. Sound Energy (noise coming from the buzzer) Battery Wires Buzzer

22. Law of Conservation of Energy  states that energy can be neither created nor destroyed the total amount of energy in a closed system is the same energy can be changed from one form to another, but all of the different forms of energy add up to the same total amount of energy PE = 24 J KE = 0 J PE = KE = PE = KE = 12 J 0 J 24 J A seagull steals a sandwich and drops it from a height of 7 m before eating it. What would be the sandwich’s approximate PE and KE as it falls to the ground if air resistance is negligible?

23. 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

24. 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 transformed into what type of energy? MECHANICAL ENERGY

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