4.6 Coulomb's Law Flashcards
coulombs law
What is Coulomb’s Law? What does it describe?
Coulomb’s Law describes the force between 2 point charges Q1 and Q2. It can be attractive or repulsive.
Equation describing Coulomb’s Law?
F = Q1Q2/4πE0r^2
What are the constants in Coulomb’s Law?
1/4πE0
What is E0 (value) in Coulomb’s Law?
8.85 x 10^-12 (m^-3 kg^-1 s^4 A^2)
What is E0 (explanation) in Coulomb’s Law?
How easy it is to form an electric field in that material. Known as permittivity of free space.
What is the value of the constants?
8.99 x 10^9
What does it mean if result of Coulomb’s Law is negative?
There is an attractive force between objects.
What does it mean if force from this equation is positive?
There is a repulsive force between charged objects.
What kind of a law is Coulomb’s Law? What factors does it depend on?
An inverse square law - depending on distance and charges. If distance i doubled then force is 1/4 of original value.
How can we test for Coulomb’s Law?
Using an experiment where one charged sphere is attached to a mass balance and the other is hanged above it. If they’re both charged (either by induction or putting with a circuit) - use insulating rods to avoid leaking charge. Depending on force between 2 sphere we should see an mass change when changing distance , for each value we should find that k in F (m x g) = k/r^2 is the same.
What may be problems in this experiment?
- leaking charge
- measuring from middle of objects (point charge)
What would happen in this experiment if forces is negative.
Mass should be less and therefore force as ball on mass balance will be attracted to hanging ball.
What would happen in this experiment if force is positive?
Mass should be more and therefore force as ball on mass balance will be repelled downwards by hanging ball.
