1. INTRODUCTION TO ENERGY, POWER, AND ELECTRICITY School House Rock Introduction Video 1 © Daniel L. Wilson, Dr. Michael A. De Miranda, Dr. Thomas J. Siller, & Dr. Todd D. Fantz

2. Goals  By the end of this lesson you will be able to:  Explain the basic concepts of energy vs. power.  Relate the three fundamental properties of a circuit (voltage, current, and resistance) to the flow of water.  Solve Ohm’s Law for simple circuits.  Discuss the relationships between electricity and magnetism and how these relate to modern power- generation techniques.  Build, test, improve, and explain the functionality of simple electromagnets and motors. 2

3. Let’s Come Clean  What do you know about energy?  Where does the energy we use come from?  Why is there so much talk about clean energy? 3

4. Today  What is energy?  What is power?  What is electricity?  Current, voltage, resistance, and power  What are the relationships between these parameters? 4

5. Energy So, everyone keeps talking about clean energy. What is energy, anyways? Image 1 From: The Breakthrough Institute, CA URL: http://thebreakthrough.org/blog/2007/08/in_love_wit h_the_sun.shtml http://thebreakthrough.org/blog/2007/08/in_love_wit h_the_sun.shtml 5

6. Energy  Energy, simply put, is the ability to do work  Energy must be controlled to do work effectively  Energy is most commonly measured in joules, calories, British thermal unit (Btu), and kWh  Kinetic, potential, thermal, chemical, electrical, nuclear Image 2 From: Crunch Gear URL: http://www.crunchgear.com/2009/04/0 3/ibm-could-buy-sun/ http://www.crunchgear.com/2009/04/0 3/ibm-could-buy-sun/ Image 4 From: HubPages, Inc. URL: http://hubpages.com/hub/Monster- Energy-Drink Image 3 From: American Feast's Sustainable Food Blog URL: http://blog.americanfeast.com/2009/08/missour i_wind_farm_draws_visit.html http://blog.americanfeast.com/2009/08/missour i_wind_farm_draws_visit.html 6

7. Power vs. Energy  Power, like energy, is a measure of ability to do work, but it depends on time.  Power is how much energy we can deliver in a certain amount of time  Units include horsepower, watts, foot-pounds per minute Image 5 From: Parents URL: http://www.parents.com/kids/education/reading/playdate- with-a-purpose-downloads/http://www.parents.com/kids/education/reading/playdate- with-a-purpose-downloads/ Image 6 From: Dream Road URL: http://www.dreamroad.us/bugatti-veyron-fastest-car-in-the- world/http://www.dreamroad.us/bugatti-veyron-fastest-car-in-the- world/ 7

8. Power vs. Energy Thrust SSCShuttle Transporter Image 7 From: Do Something.org URL: http://www.dosomething.org/tipsandtools/11-facts-about-volcanoeshttp://www.dosomething.org/tipsandtools/11-facts-about-volcanoes Image 8 From: Top Wallpapers URL: http://www.jamwallpapers.com/wp- content/uploads/2010/09/Rocky-Mountains-3.jpghttp://www.jamwallpapers.com/wp- content/uploads/2010/09/Rocky-Mountains-3.jpg 8 Which uses more power during its formation: a volcano or a mountain?

9. Power  Power is simply Energy/Time P = E/t How can we increase power? 9

10. If it weren't for electricity we'd all be watching television by candlelight. -George Gobal Electrical Energy and Power 10

11. What is Electricity?  Atoms are made up of three primary components  Protons  Neutrons  Electrons  When electrons move from atom to atom, we call that electricity Figure 9 From: Cambridge Physics Outlet, MA URL: http://www.vtaide.com/png/atom.htmhttp://www.vtaide.com/png/atom.htm 11

12. What are electricity’s characteristics?  Voltage  The amount of “pressure” behind the electrons forcing them to move from atom to atom. You can also think about it like the steepness of a river.  Current  The quantity of electrons that pass through a wire or other conductor in one second. You can also think about it like the width and depth of a river.  Resistance  How hard it is for the electrons to move through something. You can also think about it like the number of rocks and trees and other debris slowing down a river.  Power  The ability of the electricity to do a certain amount of work in a certain time (voltage x current). You can also think about this like the overall “power” or a river (how steep it is x how much water is running in it). 12

13. Important Equations  Ohm’s Law, Georg Ohm, 1827 V=I*R  Power Equation Power Equation P=V*I 13

14. Practice Ohm’s Law  Draw the following in the blank space provided on your worksheet:  What is the current through this wire? 10 ohm resistor 5 volt battery 0.5 amps 14 Diagram 1

15. Electromagnetism 15

16. Magnetics Image 9 From: Paisley + Patterns URL: http://paisley-and-patterns.blogspot.com/2011/03/magnetic-field-pattern-what-in-world-is.htmlhttp://paisley-and-patterns.blogspot.com/2011/03/magnetic-field-pattern-what-in-world-is.html 16

17. Magnetics  Activity  Try to visualize magnetic fields using your neodynium magnets and a plastic lid Be careful, the magnets can crack and hurt you! Be careful not to spill iron filings everywhere What do you notice? Does the field shape change depending on how you orient your magnet? Cool magnet video 17

18. Electromagnetics Electricity and magnetism are inextricably linked. Whenever you see electricity, magnetism is hiding somewhere in the shadows. Whenever you see magnetism, electricity is also hiding somewhere. 18

19. Electromagnetics  A long straight wire with current running through it will create a loops of magnetic field around it Figure 2 From: the full wiki URL: http://maps.thefullwiki.org/Magnetic_fieldhttp://maps.thefullwiki.org/Magnetic_field 19 Image 10

20. Solenoids and Electromagnets  If we stack or loop a bunch of wire, we can magnify and straighten out a magnetic field. This is called a solenoid or electromagnet B=(N*I)/L Where N is the number of turns, I is the current, and L is the length of the coil  Let’s make our own electromagnets! Figure 3 From: TutorVista.com URL: http://www.tutorvista.com/physics/electromagnet- solenoidhttp://www.tutorvista.com/physics/electromagnet- solenoid 20

21. Solenoids and Electromagnets  What happened?  Did more coils always mean a stronger magnet?  One part of engineering is a process of trade-offs called optimization B=N*I/L B=N*V/(L*R 2 ) B=N*V/(L*l 2 r 2 ) B=N*V*d 2 /(L*l*k 2 ) To be effective engineers, we always have to ask questions about why we are seeing the things we do. 21

22. Motors  To create a motor, we take advantage of the fact that a current-carrying wire in a magnetic field will feel a force  The force the wire feels is always in the direction that is perpendicular to both the current and the magnetic field Figure 4 From: A technical guide to building fighting robots URL: http://homepages.which.net/~paul.hills/Motors/Motors.htmlhttp://homepages.which.net/~paul.hills/Motors/Motors.html (a)(b) 22

23. Homopolar Motor  The homopolar motor motor works by placing a short section of wire perpendicular to the magnetic field wrapping around the neodymium magnets.homopolar motor current Magnetic field Figure 5 From: Wikipedia URL: http://upload.wikimedia.org/wikipedia/commons/3/32/Motor_homopolar_flux_force.pnghttp://upload.wikimedia.org/wikipedia/commons/3/32/Motor_homopolar_flux_force.png (a)(b) (c) 23

24. Homopolar Motor  You Try!  Try to figure out a way to make a nail spin instead of a wire 24 ©Michael A. de Miranda, Daniel L. Wilson, Thomas J. Siller, & Todd D. Fantz