Originally Posted by

**A Beautiful Mind** Gah.

Question: In particle accelerators, protons can be accelerated to speeds near that of light. Estimate the wavelength in nm of such a proton moving at $\displaystyle 2.40 * 10^8$ m/s. (mass of proton = $\displaystyle 1.673 * 10^{-27}$kg)

Here's the work I've done:

It says to use deBrogile's equation:

$\displaystyle \lambda = \frac{h}{mu}$

h stands for Planck's constant = $\displaystyle 6.63*10^{-34} {kgm^2}{s}$

m for the mass = $\displaystyle 1.673*10^{-27}$ kg

u for the speed = $\displaystyle 2.40*10^8$ m/s

Plugging in...

$\displaystyle \frac {6.63*10^{-34} kgm^2}{(2.40*10^8 m/s)(1.673*10^{-27}kg})$

= $\displaystyle 1.65*10^{-15}$ m (from here , just divide by 10^(-9))

Conversion factors for nm:

$\displaystyle \frac{1m}{1*10^{-9}nm} = \frac{1*10^{-9}nm}{1m}$

And then I get wrong answers all over the place. I keep constantly getting new wrong answers and even on Yahoo they're giving me wrong answers. Totally don't know what I'm doing wrong.