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

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Brought to you by pigeons keeping statue cleaners employed worldwide's

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by study count pigeons react to magnetic fields Scientists discovered

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the pigeons could sense the earth's magnetic field with their

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beaks This allows them to navigate over long distances which

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is perfect for migration seasons you got following figure This

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shows a simplified experiment The magnetic field is produced by

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a long straight wire And the pigeons beak is treated

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as a point charge of plus ten e at a

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distance of six centimetres from the wire with the point

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charge has a velocity of five meters per second and

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is subject to a magnetic force of four times ten

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to the negative Twenty second newtons what's the magnitude of

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the current l in the wire His s subzero is

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approximately twelve times ten to the negative seventh newtons per

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ampere square and hear the potential answer Six Twelve eighteen

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Twenty four a Wow Pigeons are more impressive than we

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thought Well maybe we should stop calling them flying garbage

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rats That seems kind of disrespect We need an equation

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to find the current in this wire and we need

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to figure it out from outside the wire itself Based

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off of the magnetic field the current creates around the

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wire Let's Scroll through the equations We have crammed into

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our brain to see what would work Well The best

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equation that used for this is the equation for the

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magnitude of a magnetic field which equals that constant of

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vacuum permitted ity times the current divided by two pi

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times Distance Yeah all right But to use this equation

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we first have to find the magnitude of the field

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more scrolling Sometimes it feels like if we memorize one

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more equation we won't have enough power left over to

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remember our own name Okay we can use the equation

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for the force of a magnetic field that equals charge

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times velocity times the magnitude of the magnetic field right

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there and with a little algebraic crust o change Oh

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we see that the magnitude of the field equals the

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force divided by the charge times the velocity Now we

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have two equations that both equal the magnitude of the

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magnetic field which means the equations also each other And

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we can rearrange the equation to solve for the current

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Well finally we can plug in the numbers and do

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some math But hold on let's make things easy on

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ourselves with a little rounding fir e the unit of

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charge will round that up to two times ten to

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the negative nineteenth coolum And for pie will round that

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down to three Okay we can't stand me into his

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patient any longer Let's all this already the current equals

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two times pi three times the distance six times ten

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to the negative second meters times the force which equals

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four times ten to the negative twenty second newton's All

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of that is divided by the quantity of charge ten

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times two times ten to the negative nineteenth times the

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velocity five meters per second time's the electric constant twelve

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times ten to the negative seventh newtons per amber's square

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But once we put all this together we find that

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the current equals twelve amps making answer Be the winner

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So we'll give credit where it's due pigeons have super

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powered beaks Maybe that would be a cool superhero pigeon

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boy able to sense magnetic fields with his known it 00:03:25.738 --> [endTime] is better than another spider man reboot Oh

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