## 1B #19

$c=\lambda v$

Kelly Cai 4D
Posts: 55
Joined: Sat Jul 20, 2019 12:17 am

### 1B #19

Protons and neutrons have nearly the same mass. How different are their wavelengths? Calculate the wavelength of each particle when traveling at 2.75 x 10^5 m/s in a particle accelerator and report the difference as a percentage of the wavelength of the neutron.

KSong_1J
Posts: 101
Joined: Thu Jul 11, 2019 12:17 am

### Re: 1B #19

To calculate the different wavelengths, use de Broglie’s equation (λ = h/mv) and you just search up the mass of the proton and neutron because they’re set values and plug those in for m, plug in 2.75 x 10^5m/s for v, and plug in Planck’s constant for h:

Proton:
(6.626 x 10^-34Js)/(1.673 x 10^-27kg)(2.75 x 10^5m/s) = 1.44 x 10^-12 m

Neutron:
(6.626 x 10^-34Js)/(1.675x10^-27kg)(2.75 x 10^5m/s) = 1.44 x 10^-12 m

From the equation, you can see that the wavelengths don’t seem to have much of a difference/are identical