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Notes: Name: __________________________

Stamps: Period: _______

NNOTESOTES SSTATICTATIC E ELECTRICITYLECTRICITY - E - ELECTRICITYLECTRICITY

Directions: Fill in the blanks and boxes in the note panel. After notes are done, part of your homework is to fill in the sides with study questions and write a summary that demonstrates you understand what is important in the notes.

ChargesQuestions/Main Ideas Main Notes

Charges:

• Rubbing plastic or glass makes them ______________ to bits of paper or dust

• Benjamin Franklin Decided to call the charge given to rubbed glass

___________________

Explore Electrostatics with Scotch Tape

1. Draw a picture for 3 different combinations of tape when brought near each other.

2. Draw arrows to show the direction of force on the tape

3. Write a law that explains what is happening.

• Object charged the same way will _________ each other

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• Oppositely charged objects ________________ each other

• All _______________ objects either attract or repel each other

• This implies there are_________ types of charges

Electricity:

• One of the first objects to hold this charge was ______________.

• The Greek word for amber is _________________ electron

Atom

• Even though protons are much bigger (_____________ ×’s bigger than

an electron), the – and + charges are the same size.

• If an atom has equal number of electrons and protons the net charge is

_______ (________ Charge).

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Charge Rules:

In order to get a charge, an object must get ___________ protons or electrons.

The following facts help understand charges:

1. In solids, ______________ charges do not move.

But… negative charges can move!

Conductors: electrons easily ___________ throughout the material

Because like charges __________ the electrons and protons will be as evenly spaced

Conductors __________ be charged easily

Insulators: electrons mostly move around their _________

It is very _________ to charge an insulator because insulators do not allow charges to flow easily.

Conductors Insulators

2. In _____________, both types of charges can move freely

Charges need to be distributed

_________ throughout the liquid

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3. Objects want to be ________________

If given a path to the _______________, electronswill leave until the object is neutral.

This is called ___________________

Before grounding, object is ______________ charged

During grounding, extra electrons flow into the ground, making the object neutral

After grounding, object is neutral!

Summary:

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Charging ObjectsQuestions/Main Ideas Main Notes

Charging by rubbing

• Every atom ____________ electrons (e-) a certain amount

• Rubbing two objects together allows the object that attracts electrons

more to ______________ e-.

• The stealer becomes ______________ (more e-) and the object stolen

from becomes ________________ (lost e-).

• Only works if there is ______________

1. Take 2 neutral objects

2. Rub them together!

3. Charge transfers!

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• A charged ______________ touches a neutral _______________

Conduction = Charging through contact

• A charged ______________ touches a neutral _______________

• The __________ spread out so that the __________ on both are equal

Charging by conduction is charging through contact

Q1=

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Q2=

Q1= Q2=

Q1= Q2=

Induced Polarity

• How do charged objects attract ______________ objects?

• They ______________ a charge on the insulator.

Example:

• Neutral balloon has _____________ on wall’s e-‘s.

After charging the balloon:

• Electrons in the wall will be _______________

• The exposed part of the wall now acts ________________

• The negative and positive charges

__________ each other.

Induction = Induced Polarity + Grounding

You charge an object without touching it with another charged object?

1. Induce polarity with a negatively charged object

2. Ground the object with your finger

o (This allow the negative charge to flow to the ground as

it is being repelled by the negative object)

3. Remove your finger (the ground)

4. Remove the charged object – A net positive charge will be left

behind!

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List 2 things that are wrong with the movie:

Summary:

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Electrostatic Force

Coulomb’s Law

• A force is a ________ or a _________

• Electric force is _______ times larger than gravity

• Coulomb (French physicist) studied electric charge with charged metal balls

• He studied how the amount ________________________ and the distance between the balls’ centers effected the electrostatic force.

Electrical force is proportional to:

Particles with more charge (q)experience _________ force

Charges separated by a smaller distanceexperience _________ force

Coulomb’s Law Equation:

• 1 Newton is equal to about _____________ of force.

• 1 Coulomb is the amount of charge in ____________ electrons or protons.

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FE µ

FE µ

FE=

FE º

Q1 ,Q2 º

dº

Example 1:Two charged spheres, one with 1x1012 extra electrons and one with 2x1012 extra protons are separated by 50 cm. What force do they exert on each other?

Example 2:By what factor does the Electric Force change by if the distance between 2 charged spheres is doubled?

Summary:

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−+

+ −

−+

The Electric FieldQuestions/Main Ideas Main Notes

Electric Fields

All ___________________ produce electric fields

• We know that a positive charge will __________ another positive

charge and ____________ a negative one

• If we draw lines to represent this we would be drawing an __________

Rules for drawing field lines

1. Field lines always point in the direction that a ______________ test charge would move

2. Field lines always intersect charged objects at _________ angles

3. Field lines never ______________ each other.

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4. The ______________ that field lines are to each other, the greater the electric field.

Example:Draw the electric Field Lines

Summary:

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Electric Fields in ConductorsQuestions/Main Ideas Main Notes

• Imagine a charged circle

• Where can charges move to get farthest away?

• To the __________!

• The excess charge on a conductor will always be on the surface

• How would the field effect a lone charge in the middle?

Electric Potential

• Which is worse, 120 volts or 25,000 volts?

• ______________

• Energy causes ______, not Voltage!

• Voltage is _____________ per charge

V = and E =

1 volt = 1 _________ of energy per 1 _______________ of charge

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1 volt =

•What makes voltage dangerous is how __________________________

•1 Joule is about the energy required to lift half a glass of water 1 m high

•Basic outlet is ________ V

•The flow of an outlet is about ____________________

•The energy released in 1 sec would be:

E =Amount of energy to lift ____________of water 1 m high!

•Van de Graff generator carries up to _____________ V!

•But, it only flows ____ ________________/sec

•The energy released in 1 sec would be:

E =Amount of energy to lift 75 gallons of water 1 m high!

Summary:

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E=Vq

E=Vq

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