Question

calculate the electorons recoil kinetic energy if thd energy of the incident photon is 150MeV (hint:1eV = 1.6×10^-19 =10^6eV​

Answer 1

Answer:

The wavelength of a 2 eV photon is given by:

l = h c / Eph = 6.625 x 10-34 x 3 x 108/(1.6 x 10-19 x 2) = 621 nm.

where the photon energy was multiplied with the electronic charge to convert the energy in Joule rather than electron Volt.

The kinetic energy of an electron is related to its momentum by:

T = p2/2m

from which we find the momentum, p:

p = (2mT)1/2 = (2 x 9.1 x 10-31 x 1.6 x 10-19 x 2)1/2 = 7.63 x 10-25 kg m/s.

The de Broglie wavelength of the electron is then obtained from:

l = h/p = 6.625 x 10-34 / 7.63 x 10-25 = 0.87 nm