Chapter 5--Electric Force & Electricity


Homework Solutions

Key Concepts:

  • Voltage=Potential Energy per Charge = Volts = Joule/Coulomb
  • Current =Flow of Charge = Amps = Coulombs/second
  • Resistance = Resistance to Flow = Ohms = Volts/Amps What is power? P=VI = Potential Energy per charge times the number of charges flowing per second = Potential Energy used (or converted to some other form like heat or light) per second. Energy/charge x charge/time = Energy/time = Power

  • Demo:

    The Chemical Battery is described in gorry detail in the book I think the main things are:
  • The light lit up when the bars were dunked in the acid
  • There is energy associated with making the light lite. Yes.
  • Where did this energy come from?
  • A chemical reaction took place--sort of like the chemical reaction that takes place in your body when you burn calories.
  • This chemical reaction releases potential energy stored in the chemical make up of the involved parties.
  • This type of potential energy is released via the electrical forces at work in molecules and atoms.
  • This was a demonstration of the ability to convert from electrical potential energy to other forms, i.e. light. And how this can be accomplished through a chemical reaction.