Uncertainty in Speed  [ENDORSED]


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Veronica_Lubera_1A
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Uncertainty in Speed

Postby Veronica_Lubera_1A » Tue Oct 01, 2019 10:06 pm

The hydrogen atom has a radius of approximately 0.05 nm. Assume that we know the position of an electron to an accuracy of 1% of the hydrogen radius, calculate the uncertainty in the speed of the electron using the Heisenberg uncertainty principle.

So the correct answer is Delta V >= 10^8 m/s. How would you solve the question to receive this answer?

Chem_Mod
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Re: Uncertainty in Speed  [ENDORSED]

Postby Chem_Mod » Sat Oct 05, 2019 2:18 pm

I will be covering this topic in class during Week 2.

Calculate 1% of the hydrogen radius (0.05 nm) in meters and use it as the uncertainty in position, delta x, of the electron in the Heisenberg Indeterminacy (Uncertainty) Equation.

Sears 4A
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Re: Uncertainty in Speed

Postby Sears 4A » Sun Oct 06, 2019 11:07 am

I do not think we are covering this until week 2, and the week 2 homework can be from review or quantum, so maybe wait until Dr. Lavelle goes over this in lecture!

AnayaArnold_3L
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Re: Uncertainty in Speed

Postby AnayaArnold_3L » Sun Oct 06, 2019 6:13 pm

Veronica_Lubera_1A wrote:The hydrogen atom has a radius of approximately 0.05 nm. Assume that we know the position of an electron to an accuracy of 1% of the hydrogen radius, calculate the uncertainty in the speed of the electron using the Heisenberg uncertainty principle.

So the correct answer is Delta V >= 10^8 m/s. How would you solve the question to receive this answer?


Dr.Lavelle will more than likely go over this concept more in a lecture during week 2 so I wouldn't worry about it too much as of right now.

KatherineValdez_4B
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Re: Uncertainty in Speed

Postby KatherineValdez_4B » Mon Oct 07, 2019 12:03 am

I really hope he does cover it because I'm confused.

andrewcj 4I
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Re: Uncertainty in Speed

Postby andrewcj 4I » Fri Oct 11, 2019 1:33 am

I think it goes like this:
(p)(x) = (1/2)(h/2)
(p) = m(v)
From here you can plug in (0.01)*(0.05 nm) for x and solve.

andrewcj 4I
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Re: Uncertainty in Speed

Postby andrewcj 4I » Fri Oct 11, 2019 1:34 am

One additional thing for my reply, make sure you convert nm to m.

nicole-4d
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Re: Uncertainty in Speed

Postby nicole-4d » Fri Oct 11, 2019 11:14 am

andrewcj 4I wrote:One additional thing for my reply, make sure you convert nm to m.

thanks for clarifying this.

melinak1
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Re: Uncertainty in Speed

Postby melinak1 » Fri Oct 11, 2019 4:27 pm

andrewcj 4I wrote:One additional thing for my reply, make sure you convert nm to m.


ohh ok thank you!

KatherineValdez_4B
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Re: Uncertainty in Speed

Postby KatherineValdez_4B » Sun Oct 13, 2019 7:11 pm

andrewcj 4I wrote:One additional thing for my reply, make sure you convert nm to m.

Thanks for this I almost forgot to do it.

Aprice_1J
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Re: Uncertainty in Speed

Postby Aprice_1J » Fri Oct 18, 2019 9:19 pm

Another important conceptual thing to think about is that the more you know about the position of an electron, the less we know about its velocity- they have an inverse relationship.

Anvi Brahmbhatt 4A
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Re: Uncertainty in Speed

Postby Anvi Brahmbhatt 4A » Fri Oct 18, 2019 11:16 pm

andrewcj 4I wrote:I think it goes like this:
(p)(x) = (1/2)(h/2)
(p) = m(v)
From here you can plug in (0.01)*(0.05 nm) for x and solve.

Thank you for the explanation!

Claire Stoecklein 1E
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Re: Uncertainty in Speed

Postby Claire Stoecklein 1E » Sun Oct 20, 2019 2:08 pm

When you determine delta p for the indeterminacy equation, make sure to use p=mv, using the velocity given in the equation and the mass of electron, 9.109 x 10^-31.

brennayoung
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Re: Uncertainty in Speed

Postby brennayoung » Sun Oct 20, 2019 6:04 pm

This equation can be used for other atoms than hydrogen right?

Ruth Glauber 3L
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Re: Uncertainty in Speed

Postby Ruth Glauber 3L » Sun Oct 20, 2019 10:27 pm

I think you need to calculate 1% of the hydrogen radius (0.05 nm) in meters for the uncertainty.

Caitlin Ciardelli 3E
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Re: Uncertainty in Speed

Postby Caitlin Ciardelli 3E » Sun Nov 03, 2019 6:06 pm

Another way to calc uncertainty in v:

10 ms^-1 +/- .5
You can take the +/- value and multiply it by 2. This is another way to find uncertainty in v

CMaduno_3D
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Re: Uncertainty in Speed

Postby CMaduno_3D » Sun Nov 03, 2019 9:28 pm

In response to Brennayoung's question, I believe that we will only be applying this to hydrogen for now. This principle is used when measuring position and momentum of a particle.

Sara Richmond 1D
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Re: Uncertainty in Speed

Postby Sara Richmond 1D » Wed Nov 06, 2019 1:29 pm

Use these equations:
(delta p)(delta x) = (1/2)(h/4 PIE)
(deltap) = m( delta v)

Sometimes this type of problem can be confusing because they dont give you the delta p equation.

Also remember to multiply the delta v uncertainty by 2 because it is plus or minus a certain amount.

Mitchell Koss 4G
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Re: Uncertainty in Speed

Postby Mitchell Koss 4G » Tue Nov 12, 2019 10:24 am

Also, don’t confuse frequency (v) with velocity (v)


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