Download Quick notes The ElectricField

Quick notes The Electric Field
Make sure to read pg. 453-459
1. Electric forces act over distances meaning there is a force between two
objects even if they are not touching.
2. “fields” were developed by Michael Faraday
3. An electric field goes out from every charge
4. If a second charge is placed near a first charge, it feels a force exerted by the
electric field.
5. A test charge can be used to investigate an electric field
6. A n electric field (E) is defined as the force exerted on a positive test charge
placed at a point in space divided by the magnitude of the test charge
7. E = F/ q where is the magnitude of the test charge and is given an SI unit of
newtons per coulomb
8. E describes the effect of the charges creating the electric field and not just the
charge itself
9. For a single point charge e can also be written as: E = k Q/r2
10. Using k = ¼  e0 then E = ¼  e0 Q/r2
Problem Solving for Electric Fields
1. Draw a free-body force diagram for each object, showing all forces on that
object and determine the direction of each force remembering like
charges repel and unlike charges attract.
2. Apply Coulomb’s law to calculate the magnitude of the force each charge
produces at a given point
3. Add all the force on that object using vectors to get the resultant