## Inconsistencies in Delta Values

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

Sameer Chowdhury 1C
Posts: 41
Joined: Wed Sep 30, 2020 9:41 pm

### Inconsistencies in Delta Values

For the Heisenberg Indeterminacy Module, number 23 asks you to find the delta V given that the position is +/- 5. In order to get this question right you need to then make your delta X = 10. This contradicts what is said in the textbook. In 1B problem 27 you are similarly asked to find delta V given that position is 5 +/- 5. In order to get this problem right the delta X has to equal 5. If I see a question like this on the midterm which should I use as my delta value, given it is +/- y? Should the delta be y or 2y? I assume I need to use 2y given that matches up with the problem in the module and Dr. Lavelle made the module and presumably that problem but I'm not sure.

Racquel Fox 3L
Posts: 43
Joined: Wed Sep 30, 2020 10:11 pm

### Re: Inconsistencies in Delta Values

I'm pretty sure that you generally do 2*y in order to get delta y because that is the same as (5+5 + 5-5). I'm not sure if the textbook is flawed, but I think unless there is a given value for delta y, you would multiply the number after the +/- by 2 in order to find it.

Samantha Tolentino 2B
Posts: 69
Joined: Wed Sep 30, 2020 10:03 pm

### Re: Inconsistencies in Delta Values

If the uncertainty is given as a +/- we use the difference. For example, uncertainty 10 +/- 5 therefore the uncertainty we would use would be 10. However when the uncertainty is just given, diameter of an atom is " " then we would use that value. Hope this helps!

Varsha Ravi 2C
Posts: 39
Joined: Wed Sep 30, 2020 9:48 pm
Been upvoted: 1 time

### Re: Inconsistencies in Delta Values

If the problem gives you +/- [a number, let's say it's 5], then the uncertainty would be twice that, or 10. I believe the answer to 1B.27 is an error in the textbook which shows up on the solution manual errors on the website.

Audra Mcleod 3D
Posts: 45
Joined: Wed Sep 30, 2020 9:49 pm

### Re: Inconsistencies in Delta Values

Hello!
The answer to this problem is most definitely an error, as the uncertainty in velocity would be 10 m/s not 5. Mr. Lavelle corrected this in his "Solution Manuel Errors 7th Edition" on his website, and included the correct answer.