Physics 9702 · AS & A Level · Energy and momentum of a photon
Energy and momentum of a photon — practice question
As shown in Fig. 11.1, a photon with wavelength $540\,\text{nm}$ strikes an isolated electron that is initially at rest. The electron deflects the photon elastically. 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, add an arrow to show the approximate direction in which the deflected electron moves.
(b(i))[2]
Calculate the energy transferred to the deflected electron.
(b(ii))[2]
Calculate the energy passed to the deflected electron.
(c)[2]
A further photon with wavelength $540\,\text{nm}$ collides with an isolated stationary electron. Explain why the deflected photon cannot end up with a wavelength below $540\,\text{nm}$.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “A quantum of energy” …