Electrostatics

1
Electrostatics

• Chapters 32 and 33

2
Electrostatics

• The study of electricity at rest
• Electrical forces are much stronger than
  gravitational forces

3
Charges

• Electron negative (all identical)
• Proton positive (all identical)
• Neutron no charge
• Like charges repel
• Opposite charges attract

4
Electrical Forces

• Underlies all chemical reactions
• Strongest when close together
• Ions
• Positive more protons than electrons
• Negative more electrons than protons

5
Electrical Forces (continued)

• When an atom has same number of electrons and
  protons it has a net charge of zero
• Gravity only attraction
• Electrical attraction repulsion

6
Hydrogen

• One proton one electron
• Each particle surrounded by gravitational
  electric field

7
Conductors

• Electrons are free to roam
• Loosely bound

8
Insulators

• Electrons tightly bound in place

9
Lightning Strikes

• Safest inside a steel building or a car
• Electrons flow around on the outside
• The electric field strength inside a conductor
  will be zero

10
Charge

• Induction
• Friction
• Touching

11
Charge Polarization

• A balloon sticks to a wooden wall
• Induced opposite charges closer than other wall
  charges

12
SI Units

• Unit of charge is COULOMB
• Unit of Electric Potential is VOLT

13
Van de Graff Generator

• Electrons are on the outside surface of the
  sphere
• Electric field inside dome is zero
• The generator builds up high voltages