What is the de Broglie wavelength for an electron that travels at 90% the speed of light?

1 Answer
Aug 29, 2017

See below

Explanation:

First we need to know the formula. It is, λ = h/(mv)
we know speed of light is 3.00 xx 10^8m/s, then we need to find what 90% of that is.
To find that we do this,

0.90c = 3.00 xx 10^8 "m/s" xx 0.90

=2.7 xx 10^8 "m"//"s"

λ = h/(mv)

λ= wavelength

h= Planck's constant, which is 6.63 xx 10^-34 "m"^2 cdot "kg"//"s"

m= mass of electron, which 9.11 xx 10^-31 "kg"

v= velocity

lambda =(6.63 xx 10^-34 "kg"cdot"m"^2//"s") / ((9.11xx10^-31 "kg") xx (2.7xx10^8 "m/s"))

=> lambda= 2.70 xx 10^-12"m"