a. A γ-quantum of electromagnetic radiation of frequency ν, colliding with a
stationary particle, began to move at an angle θ to the original direction. In
this case, the quantum frequency decreased by ∆ν≪ν. Determine the mass
of this particle.
b. A photon of frequency ν, colliding with a stationary electron, begins to
move at an angle θ to the original direction. Determine the change in photon
frequency if hν≪ m c2.
e