## Heisenberg equation hw problem

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

Sydney Takeda 2I
Posts: 62
Joined: Fri Sep 28, 2018 12:17 am

### Heisenberg equation hw problem

I was doing problem 1.45 in the 6th edition textbook and used the Heisenberg equation (△p△x ≥ h/4π) and solved for △x — making the equation △x ≥ h/(4πm△v) — and got my answer, then when I was checking it in the solutions manual the problem was worked out using △x = (1/2)(h/m△v), but I got the same answer. Can someone explain the reason for using the second equation, with 1/2, instead of the one with 4π?

Te Jung Yang 4K
Posts: 63
Joined: Fri Sep 28, 2018 12:18 am

### Re: Heisenberg equation hw problem

I think you might have misread the manual. It uses the h with a dash on top (ħ), this is not Planck's Constant, which does not have the additional stroke.

ħ = h / 2pi

So, the solution manual is correct, if you simply used the substitution on top for the formula used in the manual, you would get the formula that you used. But, your answer should still be correct.