Physics Quiz - Electrostatics

scientifc notation - determine exponent pos or neg

positive exponent if large number

negatice exponent if tiny number

charge

is a property of certain subatomic particles, it causes those particles to exert forces on each other over a distance. (this is electric charge. gravitational charge would be mass)

in an atom, what sign is proton, electorn and neutron

proton: + charge

electron: - charge

neutron: no charge (electrically neutral)

how do charges interact (electic force)

opposite charges attract, like charges repel

what does it mean to be “charged” (net charge)

“charges” or “net charge” - an imballance of protons and electrons

what does it mean to be “uncharged” (no net charge)

“uncharged” ,“neutral”, or “no net charge” - equal number of protons and electrons

what is the symbol for charge

the symbol for charge is q

what is unit for charge

the unit for charge in coulomb (C_

qelectron=

qelectron= -1.6×10^-19 C

qproton=

qproton= +1.6×10^-19 C

e=

e= +/- 1.6×10^-19

in q=ne, what is q

in q=ne, q is net charge

in q=ne, what is n

in q=ne, n is number of unbalanced charges

in q=ne, what is e

in q=ne, e is +/- 1.6×10^-19 C (the charge of one of the unbalaned charges)

in a gravity analogy, what is a charge

in a graviy analogy, charge is a measurable property that causes the electic force, just like how mass is a measurable property that causes gravitaional force

gravitiational force between two masses

Fg= Gm1m2/r²

in Fg= Gm1m2/r², what is m1 and m2

in Fg= Gm1m2/r², m1 and m2 are the masses putting force on each other

in Fg= Gm1m2/r², what is r

in Fg= Gm1m2/r², r is the distance between the centers of the masses

in Fg= Gm1m2/r², what is G

in Fg= Gm1m2/r², G is 6.67×10^-11 and is the gravitational constant used every time

inverse square law

inverse:

distance increase - Fg decreases

distance decrease - Fg increase

square:

disrance changes by factor of: gravitional force changes by factor of:

2 1/4

3 1/9

10 1/100

1/5 25

coulombs law

electrial force between 2 charges, F=kq1q2/r²

in F=kq1q2/r², what is Fe

in F=kq1q2/r², Fe is electic force (+repels, -attracts)

in F=kq1q2/r², what is q1 and q2

in F=kq1q2/r², q1 and q2 aew the charges putting force on each other

in F=kq1q2/r², what is r

in F=kq1q2/r², r is the distance between the center of the charges

in F=kq1q2/r², what is k

in F=kq1q2/r², k in 9×10^9 - electical constant

coulombs law, also INVERSE SQUARE

distance increases by x, Fe decreases by x²

distance decreases by x, Fe increase by x²

just because a charge is attracted or repelled, does not mean

just because a charge is attracted or reppelled, does not mean it will move

protons: dont typically move without the whole material object moving

elecrons: are often, but not always, able to move through an object, or from object to object

what type of materials can electrons easily pass through?

conductors: electrons easily move through (Ex: metal, water, people)

insulators: electorns cannot easily move through (Ex: wood, rubber, plastic, air, etc)

law of conservation of charge

you cant destroy or create charge, you can only transfer it (almost always electrons), to keep the total the same

methods of charging

friction, polarization, conduction, induction

charging by friction

when you rub 2 insulators together one may take electrons from the other. Both become charged, one +, one -

polarization

• when you bring a charged object near a neutral object it can cause the charges to move to separte sides of the neutral object.

• always attrated to the polarizing char

charging by conduction (aka contact)

if you bring a charged object into contact with a conductor electrons will transfer causing that object to share its charge with the conductor

grounding

connecting a charged object to the ground (or a large conductor) will make the object neutral

charging by induction

• is charging by polarization made permaneny by either physically separting the two sides or by grounding one side

• induces the opposite charge than the initial polarizing charge

what are the starting objects for charging by friction

for charging by friction you need 2 neutral insulators

what is the action for charging by friction

for charging by friction the action is rub the two together

what is the result for charging by friction

for charging by friction the result is both end up charged, one + charge, one - charge

what are notes for charging by friction

for charging by friction the notes are electrons tranfer from the object with lower electron affinity to the object with higher electron affinity

what are starting objects for charging by polarization

for charging by polarization the starting objects are 1 charged object and 1 neutral object

what are the actions for charging by polarization

for charging by polarization the action is bring the charged object close bu the nrutral one (if the neutral object is an isulator they can touch)

what is the result for charging by polarization

for charging by polarization the result is the neutral object retains the overall neutral charge, but the charge separates into a + and - side

what are notes for charging by polarization

for charging by polarization the notes are the attrative charge is always closer to the polarizing charge. this temporarty, one the polarizing charge is removed it goes back to neutral

what are the starting objects for charging by conduction

for charging by conduction the starting objects are 1 charged object and 1 neutral conductor

what are the actions for charging by conduction

for charging by conduction the action is touch the charged object to the conductor

what is the result for charging by conduction

for charging by conduction the result is the intital charge is shared. both end up charged the same as the original charged object

what is notes for for charging by conduction

for charging by conduction the notes is the original loses some of its charge so it is less charged, but not all the way back to neutral

what are the starting objects for charging by induction

for charging by induction the starting object is 1 charged object and 1 neutral conductor

what is the action for charging by induction

for charging by induction the action is polarize, ground the far side, remove the ground, then remove the polarizing charge

what is the result for charging by induction

for charging by induction the result is the neutral object ends up the opposite charge of the original polarizing charge

what are the notes for charging by induction

for charging by induction the notes are you can also make the polarization permanent by just physically separating the two sides, so they are insulated from each other.

what are the starting objects for grounding

for grounding the starting object is 1 charged object

what are the actions for grounding

for grounding the action is make a conductive connection to the ground (or to a much larger conductor_

what is the result for grounding

for grounding the result is the object ends up neutral

what are the notes for grounding

for grounding the notes are the ground takes electron from the charged object if it was negatively charged. the ground gives electrons if the object was positively charged