The common name is valve cover, so the correct answer is A.
Answer:

Explanation:
As per energy conservation we know that the electrostatic potential energy of the charge system is equal to the initial kinetic energy of the alpha particle
So here we can write it as

now we know that


z = 79
here kinetic energy of the incident alpha particle is given as

now we have

now we have

Absolute strength measures strength adjusted for your body size, while relative strength measurses maximum strength exerted in a single effort. Hopefully that helps wasn't really sure what you were asking seemed like you had answered your own question.