Physics 9702 · AS & A Level · Energy and momentum of a photon
Energy and momentum of a photon — practice question
A photon with wavelength $540\,\text{nm}$ strikes an isolated stationary electron, as shown in Fig. 11.1. The electron causes the photon to be elastically deflected. The wavelength of the scattered photon is $544\,\text{nm}$.
(a(i))[2]
State the meaning of a photon.
(a(ii))[1]
On Fig. 11.1, draw an arrow showing the approximate direction of travel of the deflected electron.
(b(i))[2]
Calculate the momentum of the deflected photon.
(b(ii))[2]
Calculate the energy transferred to the electron.
(c)[2]
Another photon of wavelength $540\text{ nm}$ collides with an isolated stationary electron. Explain why the deflected photon cannot have a wavelength less than $540\text{ nm}$.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “energy quantum” …