## Question 1.43

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

Posts: 26
Joined: Wed Sep 21, 2016 3:00 pm

### Question 1.43

The problem reads: What is the minimum uncertainty in the speed of an electron confined to within a lead atom of diameter 350. pm? Model the atom as a one-dimensional box with length equal to the diameter of the actual atom.

I looked at the solutions manual and h is being solved for. I am confused because I thought h was a constant (6.626 x 10 ^-34), so why do we need to solve for it?

Thank you!

Manpreet Singh 1N
Posts: 41
Joined: Wed Sep 21, 2016 2:59 pm
Been upvoted: 1 time

### Re: Question 1.43

Hello,

h is a constant. However in this answer manual it uses h bar, which is equal to h/(2pi)
when you do the math (6.626x10^-34)/(2pi)=1.0546x10^-34.

just to make it clear (h bar)/2 is the same as h/(4pi).

in the solution manual it has 1/2 separated. But if you do it with h/4pi instead, you should get the same answer.
Hope that helps :)