2. In a Compton scattering event, an incident photon is scattered by a free electron initially at rest. h (where h is the Plank constant; m.c (i) If the scattered photon acquires a wavelength 1' mẹ is rest mass of electron; c is free-space light velocity), show that the scattered photon propagates in a direction perpendicular to that of the scattered electron. If the scattered electron propagates with kinetic energy 127.8 keV in a direction opposite to that of the scattered photon, as shown in Figure 2. Find the angle 0, and therefore determine wavelengths of the incident and scattered photons, respectively. (ii)

2. In a Compton scattering event, an incident photon is scattered by a free electron initially at rest. h (where h is the Plank constant; m.c (i) If the scattered photon acquires a wavelength 1' mẹ is rest mass of electron; c is free-space light velocity), show that the scattered photon propagates in a direction perpendicular to that of the scattered electron. If the scattered electron propagates with kinetic energy 127.8 keV in a direction opposite to that of the scattered photon, as shown in Figure 2. Find the angle 0, and therefore determine wavelengths of the incident and scattered photons, respectively. (ii)