PHYSICS FREAKING FINALS

papa muise please dont fail me

electric potential energy (Ep)=

-GMM/ r (scalar unit joules)

work to lift an oject

Epi + W = Epf

work to lift in orbit

Epi + W = Epf + Ekf.. or ½ Epf

F=mac circular motion

ac= v²/r or 4π²r/ T²

velocity unit

m/s

centripetal force unit

N

magnitude of centripetal acceleration

m/s²

SCENARIO 1: object on a string

FT= FC

car around a curve

FC= Ffr

mac=μFN

usually μmg

pig

FC= FTx

in x FTx= FC

FT sin=mac

in y FTcos

mg=FTcos

vertical ciruclar motions

at top:

FC= FT +FG

at bottom:

FC= FT - Fg

if outside circle

FC= Fg - Fn

for objects in orbit

force of gravity from central object keeps object in orbit

universal gravitation formulas

Fg= Fc, ac= g = GM/ r²

v²/r =…

GM/ r² = 4π²r/ T²u

centripetal acceleration unit (ac)

N

gravitational field strength unit (g)

N/kg

acceleration due to gravity unit

m/s²

ETOTAL=

-GMm/2r

to move smth from one height to another

Epi+ W= Epf

launching smth from planet surface to h

Epi + Eki= Epf

ETOTAL (In orbit)

ET = Ep or EK= -½ Wpsuraf

surface into orbit

-GMm/ri + W = - GMm/2rf

orbit into orbit

½ Epi + W = ½ Epf

elementary charge

smallest division of charge (+ proton, - electron_

interactions with charges

like repel, opposite attracts

electrostatics equations

FE= KQq/ r², left - right if positive left, if negative right

electric fields

exist around any charged object, determines how much electric force acts on a chrage placed at a locationF

F= Eq

Force= N

E= electric field N/C

Q= charge in C

electric field lines show how positive charge will move..

+ away from +

+ towards -

how does + charge move in b fields

moves with field lines

how does - charge move in b field

goes agiainst field lines

E= KQ/ r²

E= electric field N/s, vector

v =

KQ/ r = Ep/ Q, scalr unit volt (J/C)

accelerating parallel plate system

used to speed up charges Q△v = △EK

deflecting parallel plate sysytem

used to change direction of charge E= △v/d

F= EW

F=ma

m= △v/d (Q)

magnets

material that creates magnetic field

magnetic forces

like repel, opposite attract

magnetic field

tells direction that north end of compass will point when placed in magnetic field (VECTOR)

unit = T = N/cm/s

b moves..

away from north, towards south

RHR #1

force on a current carrying wire

fingers - b

thumb - i

palm - force

F= BiL

RHR #2

force on a moving charge

finger - b

thumbs - v

force - palm +, knuckles -

Fb= QvB

the calculation for RHR #2

QB= mv/ r

F = ma

RHR #3

fingers - curl to b

thumb- curl to i

i out = ccw

I in = cw

B=μ(N/L)(i)

RHR #4

direction of B in solenoid

fingers - curl to i

thumb - b

magnetic induction

can use magnets to generate electricity

• requires change in amount of B field passing through solenoid

magnetic flux

amount of b passing through an area

flux unit

wb

inducing current

creates voltage (electromotive)
E=-N△flux/△t

N= # loops in wire

the negative sign tells us..

induces current creates a b to oppose the change in flux

if b gets STRONGER or loop WEAKER

△B= IN

BIND= OUT

I CCW

if b gets WEAKER, loop STRONGER, or changes direction

△B= OUT

BIND= IN

I CW

magnetic inductionin moving conductor

seperating charge creates E

E= BLv

V= IR

if b field INCREASES, E-

if b field DECREASES, E+

transformers

device that uses magnetic induction to convert voltage for different usesstep

step up

v increases from low to high

step down

v decreases form high to low

transformers theory

current is created in secondary coil by b created in primary

vp/vs = is//ip = np/ns