If helium nuclei and protons are each accelerated from rest through the same potential difference,how do the resulting speeds compare?

Question

Quizplus · Accepted Answer

The kinetic energy gained by a charged particle accelerated through a potential difference is equal to the charge times the potential difference. Since the helium nucleus (alpha particle) has twice the charge and four times the mass of a proton, it will have a lower speed compared to the proton when accelerated through the same potential difference. The speed ratio is determined by the square root of the mass ratio, which is √(4/1) = 2, but since the charge is also doubled, the speed ratio becomes √(2/1) = 1.4.

If Helium Nuclei and Protons Are Each Accelerated from Rest