A proton and an alpha particle are selected from a beam such that both have exactly…
PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation
Problem
A proton and an alpha particle are selected from a beam such that both have exactly the same linear momentum.
(i) State the relation connecting the de Broglie wavelength λ of a particle with its momentum p.
(ii) Without performing any numerical calculation, identify which of the two particles has the longer de Broglie wavelength when their momenta are equal. Justify your answer clearly.
(iii) Suppose instead that the proton and the alpha particle each possess the same kinetic energy of 5.0MeV. Which particle now has the longer de Broglie wavelength? Support your conclusion with suitable reasoning and any necessary mathematical steps.