Electric Potential and Wave Nature of Matter

[quicksilver123]

Homework Statement

An electric potential difference accelerates electrons from rest position towards a screen.
Just before striking the screen, the electrons have a wavelength of 1.0*10^-11 m
Find the electric potential difference.

Homework Equations

p=h/λ
ΔE_K=qΔV

The Attempt at a Solution

p=h/λ
mv=h/λ
v=h/λm
v=(6.63*10^-34)/((1.0*10^-11)(9.11*10^-31))
v=72777167.95 m/s

ΔE_K=qΔV
E_K2-E_K1=eΔV
0.5(9.11*10^-31)(72777167.95)^2 - 0.5(9.11*10^-31)(0)^2 = eΔV
ΔV=0.5(9.11*10^-31)(72777167.95)^2 / e
ΔV=15078.51948 V

Is this correct? (other than significant digits)

 

[jedishrfu]

Once again your v=(6.63*10^-34) / ( (1.0*10^-11) * (9.11*10^-31) )equation needs some parens

and your v result needs to be significant figure adjusted to be 7.28 x 10^7 m/s

similarly for the delta v result.

Again the physics looks right but someone at PF needs to second it for me.

 

[quicksilver123]

fixed.

the question wasn't asking for velocity so i didn't round it in order to get a more accurate result for electric potential difference