Answer: Time.
Explanation:
Hey there!!!
The reason is,
According to the question we have,
Initial velocity = 0m/s { as it starts from rest}.
Final velocity = 650 m/s
acceleration = 5m/s^2.
Looking on this formula,

Where "v" represents final velocity, "u" represents initial velocity and "a" represents acceleration. We dont have is time "t".
So, it's obvious that tine is an unknown variable.
<em><u>Hope</u></em><em><u> </u></em><em><u>it helps</u></em><em><u>.</u></em><em><u>.</u></em><em><u>.</u></em>
An 'alpha particle' is the same thing as the nucleus of a helium atom ...
a little bundle made of 2 protons and 2 neutrons.
A 'beta' particle is an electron.
The mass of an alpha particle is more than 7,000 times the mass of
an electron, so it certainly takes more energy to get it moving.