A photon of wavelength collides with a stationary electron and is scattered at

PHYSICS · Single correct · A Level · Physics · Particles and radiation · Particles and radiation

Problem

A photon of wavelength

0.040\,\text{nm}

collides with a stationary electron and is scattered at

90^{\circ}

. Assuming the electron’s speed remains non-relativistic, what is the approximate kinetic energy of the electron after the collision? Constants:

h = 6.63\times10^{-34}\,\text{J}\,\text{s}

c = 3.00\times10^{8}\,\text{m}\,\text{s}^{-1}

m_e = 9.11\times10^{-31}\,\text{kg}

1\,\text{eV}=1.60\times10^{-19}\,\text{J}

(a)

0.9\,\text{keV}

(b)

18\,\text{keV}

(c)

1.8\,\text{keV}

(d)

3.6\,\text{keV}