# De Broglie wavelength

1. Sep 19, 2015

### Safinaz

1. The problem statement, all variables and given/known data

A particle of mass m and charge q is accelerated across a potential dierence V to a non-relativistic velocity. What is the de Broglie wavelength of this particle?

2. Relevant equations

Is it

3. The attempt at a solution

I think it's
$\frac{h}{\sqrt{2mqV}}$, because $qV = \frac{p^2}{2m}$ , or : P.E (at rest) = K.E (after acceleration), so that $p= \sqrt{2mqV}, \lambda= \frac{h}{p}= \frac{h}{\sqrt{2mqV}}$

2. Sep 19, 2015

### blue_leaf77

You can boost your confidence by using the fact that the provided options all have different units.

3. Sep 20, 2015

### Safinaz

$(\frac{h}{\sqrt{2mqV}} )^2 : \frac{J^2 . s^2}{kg.C.volt} = \frac{kg^2 . m^4}{s^2} \times \frac{A . s^3}{kg. C. Kg. m^2}$
$= m^2 \times \frac{C/s. s}{C} = m^2$

4. Sep 20, 2015

### blue_leaf77

Well then you have found the answer.

5. Sep 20, 2015

Thanks :)