### What's the right equation?

Posted:

**Mon Oct 21, 2019 12:24 am**Is the right equation △p△m ≥(h/4π) or △p△m ≥(1/2)h???

Lavelle and the solutions manual say different things...

Lavelle and the solutions manual say different things...

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=19&t=48459

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Posted: **Mon Oct 21, 2019 12:24 am**

Is the right equation △p△m ≥(h/4π) or △p△m ≥(1/2)h???

Lavelle and the solutions manual say different things...

Lavelle and the solutions manual say different things...

Posted: **Mon Oct 21, 2019 12:42 am**

If you're referring to the Heisenberg Uncertainty Equation, it should be the first one.

Posted: **Mon Oct 21, 2019 11:31 am**

Both are the same equation. This is because the h is actually h bar and stands for h/2pi. 1/2 (h bar) would then be the same as the first equation as it is h/4pi.

Posted: **Mon Oct 21, 2019 12:47 pm**

If I'm thinking of the same question you're referring to (1B.27), there is an error in the solutions manual that Lavelle noted in his "Solution Manual Errors 7th Edition" PDF on his website. In this question, the textbook utilized that equation (1/2 h) instead of the one taught in class. If you refer to his correction, this question makes a lot more sense. Hope this helps!

Posted: **Mon Oct 21, 2019 1:14 pm**

It should be the first equation!

Posted: **Mon Oct 21, 2019 4:35 pm**

the first one should be the equation for heisenburg's uncertainty principle

Posted: **Fri Nov 01, 2019 1:16 pm**

I was confused about this too, but its the first equation with the 4pi.

Posted: **Fri Nov 01, 2019 1:23 pm**

it should be the first equation for simplicity purposes. the second equation is the same thing as long as the "h" there is supposed to be an "h bar".