What is the maximum frequency photon of one of the photons produced when a electron and positron annihilate each other?
First we must remember that a positron is the antiparticle of the electron, meaning that they will both have the same amount of rest energy (0.510999 MeV) however since annihilation produces 2 gamma photons each photon will have the same rest energy as one of the particles (0.510999 MeV). We then use the equation E=hc/λ rearranged to λ=hc/E and then sub in:(6.63x10-34)(3x108)/(0.511x106)(1.60x10-19) Notice here that in the denominator i have converted (0.510999 MeV) into MeV and then multiplied by the charge of an electron to get the energy in Joules (J) .
This then gives us the maximum wavelength of a single photon during a photon-positron annihilation: 2.43x10-12m
Related Physics A Level answers
All answers ▸An electron moving at 1000 m/s annihilates with a stationary positron. What is the frequency of the single photon produced?
A small ball of mass 150 g is placed at a height of 20cm above the ground on an incline of 35°. It is released and allowed to roll down the slope; what will be the ball's speed when it reaches the ground? Assume friction and air resistance can be ignored.
Draw a diagram of the forces acting on the rocket as it flies vertically upwards, the rocket is flying through air not a vacuum (it's not in space yet!)
Electrons moving in a beam have the same de Broglie wavelength as protons in a separate beam moving at a speed of 2.8 × 10^4 m/s . What is the speed of the electrons?