- #1

- 62

- 0

## Homework Statement

http://www.strings.ph.qmul.ac.uk/~russo/QP/r06QPHYEX.pdf [Broken]

Question 3.

## The Attempt at a Solution

I can easily derive the equation I need, which is:

lamda = h/p

Which after some playing around with K.E =1/2mv^2 etc we obtain:

lambda (de brogile) = h/SQRT(2mKE)

Here is the data we are provided with in the exam (see sheet 1): http://www.strings.ph.qmul.ac.uk/~russo/QP/week6.pdf [Broken]

Everythings in eV and MeV, I plug in the values constantly, tried converting h to joules, and the electron mass to kg etc, but no avail as I don't think I know what Im doing with it, and I can't seem to obtain the real answer which is: 1.2 x10^-9m

Anyone explain how to do this quickly? I understand the theory behind this top notch but missed on how to use eV etc.

THANKS.

Last edited by a moderator: