# AP Physics 2: 1.2 Waves

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AP Physics 2: 1.2 Waves. What is the mathematical description of the wave?

AP Physics 2 | Waves |

Language | English Language |

Science Practice 2 | Using math appropriately |

### Transcript

propagating but otherwise identical waves Well one of these why

of ext is travelling in the positive ex direction what's

the mathematical description of the other wave Why x t

and here are potential answers All right here we go

Homeboy we're so excited for this We can barely stand

it We get to talk about trig identities We know

we're stuff too but trying to scream with joy too

loud Scary house to figure this out were specifically talking

about some and difference formulas But we know a standing

wave is really two waves moving in opposite directions creating

nodes of maximum destructive interference An anti nodes of maximum

construct of interference Well a standing wave of why ext

is described as a sign b plus c plus a

sine b minus e And to expand that further equals

a sign of pecos Nc plus coastline be signed c

plus eight times quantity and quality signed b cosign c

minus co signed b sci fi and your skin is

we're right down there right All right that's a mouthful

and that'll wear out of tongue We can simplify the

equations with the distributive property and then we can see

that the two versions of a co sign be sine

c cancel each other out since we're subtracting one of

them So we're left with two of a sign be

co signed c well we were given y of x

Equals four sign three t co signed seven x at

the start of the equation we can set that equation

is equal to what we just put together with that

we can find that a equals to be equals three

t and c equal seven x this means that why

x t equals to sign three t plus seven x

plus to sign three team minus seven x We're looking

at the equation we found and looking at the answer

we've already rule out a nd we know that the

way of travelling in the negative direction has to either

be to sign three tea plus seven Acts or to

sign 3 team minus seven x the only thing we

have to figure out now is the direction well because

this wave moves in the negative x direction as time

increases the accent e coefficients need tohave the same sign

and that means the answer is b remember the wave

moving in the positive ex direction will always have the

format of why x minus t on the wave moving

from right to left We'll always have the format of

why x plus team okay that was a lot of

trick identity work were emotionally drained from all the fun

we just had All we can muster is a lying 00:03:07.395 --> [endTime] down wave Now Yeah