AP Physics 2: 2.2 Systems Interactions and Changes

she's playing in front of a huge crowd She powers

through a sweet riff and the crowd goes wild Carrie

starts showboating swinging or guitar around around it flies off

the strap and smashes into the wall Talked about a

reality check She sorts through the pieces and notices that

the guitar pick up is a square coil of wire

Well maybe the broken guitar could be a science project

after all Science fair's coming up right Carrie flips open

her tax book looks for the words coil and finds

a page describing faraday's law According to this e m

f is induced in a coil within turns by a

change in magnetic floods In time carrie counts two hundred

turns in the coil and measures this side's as one

centimeter she places the coil in a uniform magnetic field

that points into the plane of the page Take a

look at this diagram right there Carrie increases be from

point Oh won t two point oh sixty in delta

t equals one s what imf is induced in the

coil and hear the potential answers one ten hundred thousand

when life hands you lemons while you make lemonade and

when life hands you a smashed guitar you make a

science project yeah we're pretty punk rock not so punk

rock that we have our own magnetic field generator though

kerry has quite the setup here right let's look at

magnetic flux First of all magnetic flux means the amount

of magnetic field passing through an area waken Think of

it like the density of a magnetic field in this

certain space so we can swap out b a for

the flocks which means our equation now shows the imf

equals the number of coils times the change in b

a over the change in time And since the area

is not changing we can bring that out Hang with

him Carrie increases the byfield from point Oh won t

two point oh sixty So the change in b equals

point Oh five tesla's Now we can plug in our

numbers and get back to rock in the house Mm

equals two hundred coils times one centimeter squared times point

oh five tesla's over one second Don't forget that with

an area of one centimeter squared it comes toh one

times ten to the negative forthe meters squared after we

do the math we find that the magnitude of imf

created is one mil eval So the correct answer is

a oh and one last thing way used a version

of faraday's law that cheats just a little bit faraday's

law expressed in this equation really should have a negative

sign in front of it negative sinus part of lens

law and it works to show the direction the current

needs to move in order to create a magnetic field

that opposes the change in floods But because this question

is really just dealing with the magnitude of voltage we

don't need to worry about the direction so don't tell

anyone but yeah we just broke the law one thrill

and remember to be careful with musical instruments They're meant

to make beautiful music that we don't want to be

smash guitars or broken drums that's or even a dented 00:03:18.22 --> [endTime] kazoo that matter