What accelerating potential difference would be required to give each of the following particles...

What accelerating potential difference would be required to give each of the following particles a de broglie wavelength of 2.0nm?
a) a proton
b)an alpha particle

The answer is
a)2.0x^-4 V
b)2.57x10^-5 V

It was easy enough with an electron but these are just hard D:


<3 Love you all

I can do one, and hopefully, you can do the other.

(a)

w = h/mv

h = planck's constant = 6.626E-34 Js
m = mass = 1.67E-27 kg
v = velocity

2E-9 = 6.626E-34 / 1.67E-27 * v

v = 198 m/s

Use the accelerating potential difference equation:

V = 0.5mv^2 / e

e = 1.6E-19 C

V = 0.5 * 1.67E-27 * 198^2 / 1.6E-19 = 2.05E-4 V