Answer:
The correct question is:
"Find the energy each gains"
The energy gained by a charged particle accelerated through a potential difference is given by
where
q is the charge of the particle
is the potential difference
For a proton,
And since 
The energy gained by the proton is
For an alpha particle,
Therefore, the energy gained is
Finally, for a singly ionized helium nucleus (a helium nucleus that has lost one electron)
So the energy gained is the same as the proton:
Answer:
finding Cepheid variable and measuring their periods.
Explanation:
This method is called finding Cepheid variable and measuring their periods.
Cepheid variable is actually a type of star that has a radial pulsation having a varying brightness and diameter. This change in brightness is very well defined having a period and amplitude.
A potent clear link between the luminosity and pulsation period of a Cepheid variable developed Cepheids as an important determinants of cosmic criteria for scaling galactic and extra galactic distances. Henrietta Swan Leavitt revealed this robust feature of conventional Cepheid in 1908 after observing thousands of variable stars in the Magellanic Clouds. This in fact turn, by making comparisons its established luminosity to its measured brightness, allows one to evaluate the distance to the star.
