What is the method of charging when you rub fur on a plastic rod?
Friction
100
What is the difference between a conductor and an insulator? Give an example of each.
conductor - materials that allow electrons to flow freely from particle to particle (example - metals)
insulator - materials that do not allow the free flow of electrons from atom to atom and molecule to molecule (examples - plastics, glass)
100
Coulomb's Law depends on __________ and __________
Charge and distance
100
What is an electric field?
the area surrounding a charge
100
The study of charges at rest.
Electrostatics
200
What are the two ways I can make the leaves on an electroscope stay separated?
Charging by conduction and induction
200
The charge of one electron or proton.
1.6x10^-19 C
200
When is the electrostatic force between two charges the strongest?
When they are really close together.
200
Lines drawn to represent an electric field extend __________ from a positive charge and __________ a negative charge.
away, toward
200
What is the formula for Coulomb's Law?
F = kq1q2/r2
300
Draw an electroscope when a negatively charged rod touches a neutral electroscope? What method of charging is this?
See PowerPoint - Conduction
300
When two spheres, one 5C and the other -13C, are brought together and separated, the charge on each is
-4C (take the average of the charges)
300
Two charged spheres are brought near each other. One has a charge of +4.0 x 10^-6 C. The other one has a charge of -4.5 x 10^-6 C. If they are 0.002 m apart, what amount of force exists between them? What is the interaction that exists between them?
4.05 x 10^4 C (they will attract because they are opposite charges)
300
Draw the electric field that exists between two positive charges.
See PowerPoint.
300
The SI unit for charge
Coulomb
400
What is it called when you touch a charged object with your hand?
Grounding
400
A sphere has a net charge of -4.8X10^-19 C. How many excess electrons are on the sphere?
3 electrons
400
Two charged spheres are brought near each other. One has a charge of +3.7 μC. The other one has a charge of +4.5 μC. If the charges are 0.75 meters apart, what is the force of repulsion between them?
0.2664 N
400
Draw the electric field that exists between an object with two excess protons and an object with one excess electron.
See powerpoint.
400
The unit for electrostatic force
Newton
500
Draw the distribution of charges in a neutral pith ball when a positively charged rod is brought near the pith ball but doesn't touch it? What is this called?
As the positively charged rod approaches the pith ball the electrons are attracted to the rod so they move toward the side of the rod. So one side of the pith ball is negative and the other side is positive. (This is called polarization)
500
A sphere has a negative charge of 6.4 X10^-7 coulombs. Approximately how many electrons must be removed in order to make the sphere neutral?
4x10^12 electrons
500
If the force between two charges is 10 N, what would the new force be if each charge was doubled and the distance was halved?
160 N
500
What does the direction of an electric field indicate?
The direction a positive test charge would go.
500
This way of charging causes the object to have an opposite charge.