ShmoopTube

00:00

Thank you We sneak And here's your shmoop du jour

00:06

Brought to you by smart french dude that's it a

00:10

man who changed the world with his discovery and advanced

00:13

all of humanity with his knowledge that's right We're talking

00:16

about the guy who invented french fries Yeah all right

00:20

Well this column fries over there all right A small

00:23

electrically receptive ball is placed on the ground One point

00:27

charged with charge q Liza distance x north of the

00:30

ball while a second point charged with charge q lies

00:33

an equal distance x west of it If the distance

00:37

between the point charges and bolus doubled what's the new

00:40

electric force exerted on the ball All right assume that

00:43

the original electric force on the ball is well we

00:45

call it tea All right And here the essential And

00:48

they're so some version of pete a long long time

00:52

ago in a galaxy Well actually in our galaxy And

00:55

it wasn't that long ago actually let's Just start over

00:57

back in seventeen eighty five charles augustin to comb discovered

01:01

a law of physics which now bears his name And

01:04

no it's not charlie's law It's cooling is lost and

01:07

it states that electric force exerted at a point between

01:09

two point charges equals ghoulam's constant times the product of

01:13

the charges divided by the square of the distance between

01:16

the charges That's the equation right there Okay And because

01:19

of that last part we know that we have an

01:21

inverse square relationship at work We've seen this with radiation

01:25

from a point source Remember that if not it's Okay

01:28

we can't remember what we had for lunch All right

01:30

wait Even have lunch yet we're going to go You

01:33

can just be on safe sex Inverse square relationships mean

01:37

that numbers start getting really small quickly If the distance

01:40

triples the forces reduced to one night And if the

01:44

distance doubles well the force exerted is one quarter is

01:47

strong No the correct answer here is just a this

01:50

question involves two point sources but on the test there

01:53

might be questions with more sources So remember that charge

01:57

sources effect each other as well as non charge objects

02:01

like the ball Obviously the math gets a little more

02:04

complicated as we had sources but we're smart enough to

02:06

handle it Unfortunately we're not smart enough to wait for

02:08

the french fries school Before we stuff them in our 00:02:10.953 --> [endTime] mouth Ouch

Full Transcript