Physics 9702 · AS & A Level · Energy and momentum of a photon
Energy and momentum of a photon — practice question
A $\pi^{0}$ meson is a sub-atomic particle. When a $\pi^{0}$ meson is at rest, and has mass $2.4 \times 10^{-28}\,\text{kg}$, it decays to produce two $\gamma$-ray photons. The nuclear equation representing this decay is $\pi^{0} \rightarrow \gamma + \gamma$.
(a)[2]
Explain why the two $\gamma$-ray photons end up with the same energy.
(b(i))[2]
Determine, for each $\gamma$-ray photon, the energy, in joule.
(b(ii))[2]
Determine, for each $\gamma$-ray photon, the wavelength.
(b(iii))[2]
Determine, for each $\gamma$-ray photon, the momentum.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Momentum conservation; photons have equal and opposite momentum” …