Electric charges and forces

Electric charges and forces

1. Electric force

   • Electric force acts along a line between the charges
   • Coulombs law describes the electric force
   • Electric force dissimilar to gravitational force
     • Similarities and Differences
     • Astronomical systems
     • Atomic systems
   • Electric forces keeps most objects close to neutral

2. Combining Electric forces

   • Electric forces can be added graphically
   • Electric forces add by vector addition
   • A spherical distribution of charge acts just like a point charge
     • Surface Charge Density

3. Electric Charge

   • Electric charge come in two distinct types
     • Positive charge
     • Negative charge
   • An electric charge can attract a neutral object
     • The polarization process
   • Rubbing objects together can charge them
   • Electric charge can be transferred between objects
     • Ion
   • A coulomb is a large amount of charge
   • Charging by contact varies with the material
     • Triboelectric Charging
     • Charging by collision
   • Not all materials are good conductors
     • Conductors
     • Semiconductors
     • Insulators
   • A coulomb is a large amount of charge