## Uncertainty in Speed [ENDORSED]

$\Delta p \Delta x\geq \frac{h}{4\pi }$

Veronica_Lubera_2A
Posts: 106
Joined: Sat Sep 14, 2019 12:16 am
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### Uncertainty in Speed

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
Posts: 18890
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 716 times

### Re: Uncertainty in Speed  [ENDORSED]

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
Posts: 36
Joined: Tue Feb 05, 2019 12:15 am

### Re: Uncertainty in Speed

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
Posts: 56
Joined: Wed Sep 18, 2019 12:19 am

### Re: Uncertainty in Speed

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
Posts: 22
Joined: Sat Sep 14, 2019 12:17 am

### Re: Uncertainty in Speed

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

andrewcj 2C
Posts: 102
Joined: Thu Jul 11, 2019 12:17 am

### Re: Uncertainty in Speed

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

andrewcj 2C
Posts: 102
Joined: Thu Jul 11, 2019 12:17 am

### Re: Uncertainty in Speed

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

nicole-2B
Posts: 103
Joined: Fri Aug 30, 2019 12:18 am

### Re: Uncertainty in Speed

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

thanks for clarifying this.

melinak1
Posts: 25
Joined: Tue Sep 24, 2019 12:17 am

### Re: Uncertainty in Speed

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

ohh ok thank you!

KatherineValdez_4B
Posts: 22
Joined: Sat Sep 14, 2019 12:17 am

### Re: Uncertainty in Speed

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
Posts: 55
Joined: Wed Sep 18, 2019 12:16 am

### Re: Uncertainty in Speed

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
Posts: 51
Joined: Wed Sep 18, 2019 12:21 am

### Re: Uncertainty in Speed

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

Thank you for the explanation!

Claire Stoecklein 1E
Posts: 49
Joined: Sat Jul 20, 2019 12:15 am

### Re: Uncertainty in Speed

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
Posts: 51
Joined: Fri Sep 20, 2019 12:17 am

### Re: Uncertainty in Speed

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

Ruth Glauber 1C
Posts: 100
Joined: Wed Sep 18, 2019 12:20 am

### Re: Uncertainty in Speed

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

Caitlin Ciardelli 3E
Posts: 44
Joined: Wed Sep 18, 2019 12:19 am

### Re: Uncertainty in Speed

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

Posts: 102
Joined: Wed Sep 18, 2019 12:18 am

### Re: Uncertainty in Speed

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 2K
Posts: 110
Joined: Fri Aug 30, 2019 12:16 am

### Re: Uncertainty in Speed

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
Posts: 128
Joined: Sat Jul 20, 2019 12:17 am

### Re: Uncertainty in Speed

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

Jack_Pearce_2F
Posts: 41
Joined: Wed Sep 30, 2020 9:48 pm

### Re: Uncertainty in Speed

you would use the heisenberg uncertainty equations to solve this but more likely than not the result would be very off because the electron is known to a very close degree of certainty
The text passage contains a mathematical question and an answer to that question. The question involves calculating the uncertainty in the speed of an electron using the Heisenberg uncertainty principle, and the answer provided is \( \Delta v \geq 10^8 \, \text{m/s} \).
single_question_with_answer
Given a text passage, determine:
    1. If it contains a mathematical question (including word problems or calculations)
    2. If an answer to that mathematical question is provided in the text

First, describe the content structure you found in 1-2 sentences.

Then provide your analysis in the following format:
TYPE: <one of the following values>
- NO_QUESTION
- SINGLE_QUESTION
- SINGLE_QUESTION_WITH_ANSWER
- MULTIPLE_QUESTIONS
- MULTIPLE_QUESTIONS_WITH_ANSWERS
system
## Uncertainty in Speed [ENDORSED]

$\Delta p \Delta x\geq \frac{h}{4\pi }$

Veronica_Lubera_2A
Posts: 106
Joined: Sat Sep 14, 2019 12:16 am
Been upvoted: 1 time

### Uncertainty in Speed

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
Posts: 18890
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 716 times

### Re: Uncertainty in Speed  [ENDORSED]

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
Posts: 36
Joined: Tue Feb 05, 2019 12:15 am

### Re: Uncertainty in Speed

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
Posts: 56
Joined: Wed Sep 18, 2019 12:19 am

### Re: Uncertainty in Speed

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
Posts: 22
Joined: Sat Sep 14, 2019 12:17 am

### Re: Uncertainty in Speed

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

andrewcj 2C
Posts: 102
Joined: Thu Jul 11, 2019 12:17 am

### Re: Uncertainty in Speed

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

andrewcj 2C
Posts: 102
Joined: Thu Jul 11, 2019 12:17 am

### Re: Uncertainty in Speed

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

nicole-2B
Posts: 103
Joined: Fri Aug 30, 2019 12:18 am

### Re: Uncertainty in Speed

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

thanks for clarifying this.

melinak1
Posts: 25
Joined: Tue Sep 24, 2019 12:17 am

### Re: Uncertainty in Speed

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

ohh ok thank you!

KatherineValdez_4B
Posts: 22
Joined: Sat Sep 14, 2019 12:17 am

### Re: Uncertainty in Speed

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
Posts: 55
Joined: Wed Sep 18, 2019 12:16 am

### Re: Uncertainty in Speed

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
Posts: 51
Joined: Wed Sep 18, 2019 12:21 am

### Re: Uncertainty in Speed

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

Thank you for the explanation!

Claire Stoecklein 1E
Posts: 49
Joined: Sat Jul 20, 2019 12:15 am

### Re: Uncertainty in Speed

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
Posts: 51
Joined: Fri Sep 20, 2019 12:17 am

### Re: Uncertainty in Speed

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

Ruth Glauber 1C
Posts: 100
Joined: Wed Sep 18, 2019 12:20 am

### Re: Uncertainty in Speed

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

Caitlin Ciardelli 3E
Posts: 44
Joined: Wed Sep 18, 2019 12:19 am

### Re: Uncertainty in Speed

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

Posts: 102
Joined: Wed Sep 18, 2019 12:18 am

### Re: Uncertainty in Speed

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 2K
Posts: 110
Joined: Fri Aug 30, 2019 12:16 am

### Re: Uncertainty in Speed

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
Posts: 128
Joined: Sat Jul 20, 2019 12:17 am

### Re: Uncertainty in Speed

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

Jack_Pearce_2F
Posts: 41
Joined: Wed Sep 30, 2020 9:48 pm

### Re: Uncertainty in Speed

you would use the heisenberg uncertainty equations to solve this but more likely than not the result would be very off because the electron is known to a very close degree of certainty
user
The text passage contains a mathematical question and an answer to that question. The question involves calculating the uncertainty in the speed of an electron using the Heisenberg uncertainty principle, and the answer provided is \( \Delta v \geq 10^8 \, \text{m/s} \).

TYPE: SINGLE_QUESTION_WITH_ANSWER