Rearranging De Broglie Equation


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Alessia Renna 1D
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Rearranging De Broglie Equation

Postby Alessia Renna 1D » Wed Oct 21, 2020 11:56 am

How would you rearrange the De Broglie Equation in order to calculate velocity using wavelength, mass, and planck's constant?

Jordan Tatang 3L
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Re: Rearranging De Broglie Equation

Postby Jordan Tatang 3L » Wed Oct 21, 2020 11:59 am

Hi!

So the De Broglie Equation is shown on the formula sheet as
(wavelength) = h/p

p = momentum which is (mass)(velocity)

Therefore, you can rewrite the equation as
wavelength = h/(mass)(velocity)

If you multiply both sides by velocity and then divide both sides by wavelength you end up with

velocity = h/(mass)(wavelength)

Hopefully this helps!

Nadya Higgins 3F
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Re: Rearranging De Broglie Equation

Postby Nadya Higgins 3F » Wed Oct 21, 2020 12:00 pm

The De Broglie equation is wavelength = planck's constant over momentum. Momentum is equal to mass times velocity. So if you write, wavelength=h/mv and then isolate the velocity, you should get what you're looking for. It should come out to be v=h/(wavelength times mass)

Lisa Seidl 3H
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Re: Rearranging De Broglie Equation

Postby Lisa Seidl 3H » Wed Oct 21, 2020 12:01 pm

The original equation is (lambda)=h/mv
To rearange this, you'd want to solve for v before inputting any numbers since this makes the process a lot easier. After rearranging and solving for v, your new equation should be v=h/m(lambda)

Rob Tsai 2F
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Re: Rearranging De Broglie Equation

Postby Rob Tsai 2F » Wed Oct 21, 2020 3:32 pm

De Broglie's equation: (lambda) = h/p, where h= Planck's constant and p= momentum.

It can be further simplified to (lambda) = h/(mv), where m= mass and v= velocity, as momentum is (mass)(veloctity).

Then, we can do some relatively simple algebra to solve for velocity (v):
(lambda) = h/(mv)
(v)(lambda) = (v)(h)/(mv), where we multiply both sides by velocity (v) to isolate it to one side.
(v)(lambda) = h/m, as velocity (v) in the numerator and denominator cancel out.
v = h/(m)(lambda) is your final answer.

Hope this helps!

Aydin Karatas 1F
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Re: Rearranging De Broglie Equation

Postby Aydin Karatas 1F » Wed Oct 21, 2020 4:01 pm

The De Broglie Equation states that λ=h/p, where p=mv.

Therefore, we know that λ=h/mv.

If λ and m are given and knowing that h is a constant, we can isolate for v with v=h/λm.

The main thing to keep in mind with De Broglie conceptually is that small particles exhibit wave-like properties.

Hope this helps!

Lorraine Medina 3E
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Re: Rearranging De Broglie Equation

Postby Lorraine Medina 3E » Wed Oct 21, 2020 6:19 pm

Hi! The given equation for De Broglie is λ=h/p (where h is Planck's constant and p is momentum), we also know that p=mv (where m is mass and v is velocity). Therefore, we can substitute p in the original De Broglie equation for mv. From there, you get λ=h/mv. You can solve for velocity by multiplying both sides of the equation by mv, then dividing both sides by mλ. From there, you are left with v=h/λm.

Michael Sun Dis 3G
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Re: Rearranging De Broglie Equation

Postby Michael Sun Dis 3G » Thu Oct 22, 2020 6:29 pm

If you multiplied both sides of the equation by velocity, then divided both sides by wavelength, you'd end up with v = h / mλ.

Sophia Kalanski 1A
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Re: Rearranging De Broglie Equation

Postby Sophia Kalanski 1A » Thu Oct 22, 2020 11:53 pm

Hello!

So we know that the De Broglie Equation is originally (wavelength)=h/mv

to rearrange it so that you are trying to find the velocity, you would multiply v by both sides to cancel it out from the right side and then divide the wavelength by both sides.
You end up with v=h/(m*wavelength)

Angel Gutierrez 2E
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Re: Rearranging De Broglie Equation

Postby Angel Gutierrez 2E » Thu Oct 22, 2020 11:56 pm

When you have values with a neg exponent and they are the denominator in the equations, do you change the negative exponents as a positive since they become part of the denominator?

Jiapeng Han 1C
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Re: Rearranging De Broglie Equation

Postby Jiapeng Han 1C » Fri Oct 23, 2020 8:06 am

According to De Broglie's equation: wavelength=planck constant/momentum.
Momentum=mass*velocity
As a result, wavelength=planck constant/(mass*velocity), so velocity=planck constant/(mass*wavelength).

Kayla Booker 1F
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Re: Rearranging De Broglie Equation

Postby Kayla Booker 1F » Fri Oct 23, 2020 11:29 am

Since de broglie’s equation is wavelength =h/mv, you multiple v to both sides then divide by wavelength to get v=h/m(wavelength)

Jason_John_2F
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Re: Rearranging De Broglie Equation

Postby Jason_John_2F » Fri Oct 23, 2020 2:36 pm

You want to rearrange the equation to isolate the v which can be done simply by multiplying both sides by v and dividing both sides by λ to get v=h/mλ

Emma Ide 2E
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Re: Rearranging De Broglie Equation

Postby Emma Ide 2E » Fri Oct 23, 2020 3:32 pm

DeBroglie's equation can be rearranged in many ways to find other values.
wavelength=h/p
p= mv and
E=pc, so
pc=h(c/wavelength)
which gives the wavelength equation
these equations can all be derived from each other

Mari Williams 1K
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Re: Rearranging De Broglie Equation

Postby Mari Williams 1K » Sun Oct 25, 2020 12:24 pm

Will we likely have to derive these equations during the midterm since they're not on the equation sheet?

505598869
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Re: Rearranging De Broglie Equation

Postby 505598869 » Sun Oct 25, 2020 1:37 pm

wavelength(lambda) = planck's constant(h) / momentum(p)
p = mass x velocity
you can plug in mv for p in the wavelength equation and isolate v
you would end up with

v = h/m(lambda)

Abraham De Luna
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Re: Rearranging De Broglie Equation

Postby Abraham De Luna » Sun Oct 25, 2020 9:18 pm

(velocity)= h/(mass)(wavelength)

Simran Bains 2C
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Re: Rearranging De Broglie Equation

Postby Simran Bains 2C » Sun Oct 25, 2020 9:24 pm

(wavelength)=h/p
p=(mass)(velocity)
(wavelength)=h/(mass)(velocity)


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