Electrostatics
If on a chemical reaction a neutrak atom gains one electron, what is the net charge of this atom
-1.6 x 10^-19C
direction of a force
-opposite charges attract -like charges repel -have to look at the force on each object individually
The electrostatic force between two charges located 8 meters apart is 0.10 N. What will the force be between these charges when they are located 2 meters apart
1.6 N
Two point charges initially 4 cm apart are moved to a distance of 12 cm apart. By what factor does the resulting electric force between them charge
1/9
How is the electric force between two charges affected when the distance between the charges is halved
4 times as much
Assume a rubber rod is rubbed against a rabbit fur and gains 5 electrons. How many electrons did the fur lose
5 electrons
Two charges separated by a distance of 1 meter exert a 2-N force on each other. If the magnitude of each charge is doubled, the force on each charge is
8 N
An object with a negative charge would ___________ an object with a neutral charge
Attract
opposite charges
Attract
Electric field lines are directed _______ positive charges a _______ towards negative charges
Away from, toward
What do electrice forces do
Causes objects to repel or attract each other
charging by induction
Charging an object without direct contact between the object and a charge (requires polarization and grounding)
Charging an object with direct contact is called
Conduction
What materials charge most easily
Conductors
Which is not a good insulator
Copper
What is the unit of electric charge
Coulomb
An electric field has both what
Direction and magnitude
When a balloon is charged negatively by rubbing it on your head, what happens
Electrons are added to the balloon
The distance between two charges qa and qb is r, and the force between them is F. What is the force between them if the distance between them is doubled
F/4
How is the electric force between two charged affected when both of the charges are doubled
Four times as much
When a balloon is rubbed on clothes it acquires a charge by
Friction
What is not a good conductor of electricity
Glass
What do u call the process of charging a conductor by bringing it near anotner charged object
Induction
What is the process of charging a conductor by bringing it near another charged object and grounding it
Induction
A student touches a negatively charged rod to a neutral electroscope. What happens to the electriscope
It becomes negative
What unit is used to measure electric potential energy
Joule
An atom gains an electron. What type of charge does it have now
Negative
What is the overall charge of an object that has been charged by polarization
Neutral
Are charged objects attracted to neutral objects
No
an electroscope is given a negative charge by conduction. The electroscope is then "grounded" by touching with a finger. This means that the electroscope now has
No net charge
How is the electric force between two charges affected when the distance between the charges is doubled
One-quarter as much
Electric forces can be either attractive or repulsive. In contrast, gravitational force is
Only attractive
Two charged particles held close to each other are released. As they move, the force on each particle increases. Therefore, the particles have
Opposite signs
A student brings a negatively charged rod close to a neutral electroscope but does not touch it. The students lab partner touches the electroscope with his finger. After removing the finger touching the electroscope and the charged rod, what charge is now on the electroscope
Positive
After you rub a balloon on your hair, the balloon has a negative charge. What charge does you hair have
Positive
An atom loses an electron. What type of charged ones it have now
Positive
An atom that has more protons than electrons would have what charge
Positive
When a glass rod is rubbed with silk and the glass rod becomes positively charged, what happens to the electrons
They are removed from the rod
What happens to two like charges
They repel
What unit is used to measure electric potential
Volt
When a electron is brought near a negatively charged sphere, its potential energy increases. The reason this happens is that
Work has been done to bring the charges together
conductors
allow charge to flow freely
charging by conduction (contact)
contact of a charged object onto a neutral object
vector quantity
direction matters
The direction the electric field lines shows the
direction of the force on a test positive charge
insulator
does not allow charge to flow freely
The law of conservation of charge states that
electric charge is not created or destroyed
A positive charge and a negative charge held near each other are released. As they move, the force on each particle
increases
good conductors
metal, gold, water, copper, silver
Charge of an electron
negative
Two charges are separated by a certain distance. If the magnitude of each charge is doubled, the force on each charge is
quadrupled
When the distance between two charges is halved, the electrical force between the charges
quadruples
grounding
removal of excess charge on an object by transferring electrons to another object of greater size
Like charges
repel
polarization
separation of opposite charges within an object (not charging)
charging by friction
two objects rub together and one becomes positively charged and the other becomes negatively charged