De Broglie Wavelength of Accelerated Proton

[zimo]

Homework Statement

A proton is accelerated from rest through a potential of 1kV. Find its de Broglie wavelength.

Homework Equations

$$\lambda=h/p$$

The Attempt at a Solution

I tried to get p (momentum) by energy comparison:

e*1000=0.5*m*v^2
v=437 621.130 016 524 m/s

which doesn't makes sense... what am I doing wrong?

 

[nicksauce]

Do you mean 437621.130016524 m/s? Or 437,621,130,016,524 m/s? If the first, then that is roughly what I get when using google calculator (but why so many places after the decimal??), why doesn't it make sense to you? If the second, then that indeed doesn't make sense ,and I would recommend trying to put in the numbers again.

 

[zimo]

Oh snap!
It didn't make sense since I used Planck constant with eV*s units all the time instead of J*s units...

Thanks nicksauce.