Questions for Einstein�s Big Idea

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					Power and Efficiency
• Power = work done (or energy change) / time interval
   • Two cars accelerate from rest to highway speed
      • One does it in five seconds (Porsche)
      • One does it in ten seconds (4 cylinder SUV)
      • Which uses more power?
• Efficiency = useful energy output / Total Energy Input
   • At best 30-35% of the Chemical Energy in gas
     => Moving a car
     Car engines are at best 30-35% Efficient
     Electric motors can have efficiencies approaching 99%



                                                           Slide 10-23
Energy And Real Life
• Tour de France
  A Tour de France bicycle racer needs
  to eat 8000 calories per day to
  maintain their weight. About 65-70%
  of this energy is used to maintain
  body temperature.
• Bow and Arrows
  About 60-75% of the PE in a drawn
  bow goes into the KE of an Arrow.
  The rest of the energy heats the bow.
• Guns and Bullets
  Only about 30% of the energy in a
  firearms discharge is transferred to
  the projectiles they fire


                                          Slide 10-23
Compare Energy and Momentum
Questions for Einstein’s Big Idea
1. What did Michael Faraday discover that
   affects our every day lives
2. How did the Lavoisier’s demonstrate
   conservation of mass?
3. How did Madame de Chatelet show that
   Energy is proportional to v2
4. What does E = mc2 mean? How would you
   explain it to your friends?
5. How did Lise Meiner and associates validate
   E = mc2
6. What are some applications of E=mc2
Questions for Einstein’s Big Idea
7. What was the most interesting thing you
   learned about from watching the DVD?

8. What do thing was the most important thing
   you learned from the DVD?

9. Should I show this DVD to my next Physics
   102 class? Why or why not?
Building on Einstein’s Big Idea
1. Magnetic field from a wire
2. How a magnetic field creates electricity
3. Eddy Currents
Building on Einstein’s Big Idea
         and Beyond
1. Frames of Reference
2. Special Relativity
3. Photoelectric Effect
4. Dark Matter
5. Dark Energy
6. Global Warming

				
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