Physics Unit 1 Lecture Flashcards

What part of an atom takes up the most mass (99.9%

the nucleus

What is the mass of a proton in kg

1.67 × 10^(-27)

What is the mass of an electron in kg

9.109 × 10^(-31)

elementary charge explain it

every charge in universe is an integer of multiple of e.

elementary charge e =

1.602 × 10^(-19)

There will never be a free standin particle with a ________- charge of e

fractional (NO 2.5e or 0.5e)

Q (total charge) =

n (positive/negative integer) e (elementary charge)

what is a conductor describe how and what type of bonding

materials that allow electricity to flow through them with very little resistance (metallic bonding)

what is an insulator describe how and what type of bonding

materials that resist the flow of electrocity (electrons are tightly bound) (covalent bonding)

what are the three types of charging

tribocharching, charging by induction, and charge polarization

what is tribocharging

chargin due to contact (even distrubution through contact charging)

what is charging by induction

inducing charges with NO physical contact due to attraction

charge polarizaiton

electrons are shifted not transferred, very similar to charging by induction → on a small scare because charges are polarized (partial positive and partial negative)

the magnitude of the force between 2 charges is

F= k|q1q2|/r²

What is the equation for electric field strenght

E=F/q (E force per unit charge exerted on a test charge, F force due to an electric field on a test charge)

Force on a positive test charge points where?

in the direction of an electric field

What is the equation for electric field at a GIVEN POINT?

E=kq/r² rhat

electric field lines radiate _________ from a positive charge

out

describe the proportionality of the density of electric field lines and field strenght

the density of electric field lines are directly proportional to field strenght

true or false electric field lines never cross

true

what is a dipole

a pair of equal and opposite charges seperated by a small distance

whyat is the acceleration of a charge do to an electric field

q/m E

true or false, non polarized molecules can be polarized due to an external field

true

true or false

polar molecules have permanent dipole moments

dq=

p du

dE=

(kdq/r²) rhat

line charge

dq=lambda dl (lambda is charge per length)

plane charge

dq=lowercase sigma dA (where sigma is charge per area)

charge over a 3D volume

dq=pdV (where p is charge per volumeO

how to calculate E field for constant linear charge density

E field = integral dE = integral krhat/r² dq

field due to a infinite line of charge

E = (2klambda/R) rhat

what is a gaussian surface

an imaginary closed surface that has an inside and an outside, has enclosed charges, and can be any closed shape

what is electric flux

the net number of field lines passing through a Gaussian Surface

electric flux lines passing from outside to inside add ________ to our count

-1

lines passing from inside to outside add ______ to our count

+1

the net number of electric field lines out of a surface is proporitonal to the net __________ enclosed by that surface

charge

electric flux for a flat surface and a constant field

slashed zero= EA

electrict flux for a flat surface at angle theta to a constant field

slashed zero = EA costheta

If a surface is not flat and normal n is not constant

slashed zero = integral En da