Refraction due to attractive potential

[missmaria]

Electrons incident on a crystal suffer refraction due to an attractive potential of 15V. If the angle of incidence is 45 degrees and the electrons have an incident energy of 100eV, what is the angle of refraction?

Ok, so i know that i have to use snell's law, but I'm stuck on calculating the effect of the attractive potential of the crystal. please help! thanks

 

[olgranpappy]

Electrons incident on a crystal suffer refraction due to an attractive potential of 15V. If the angle of incidence is 45 degrees and the electrons have an incident energy of 100eV, what is the angle of refraction?

Ok, so i know that i have to use snell's law, but I'm stuck on calculating the effect of the attractive potential of the crystal. please help! thanks

The potential changes the wavelength of the electrons. Thus causing the refraction.