Answer:
Velocity of a proton,
Explanation:
It is given that,
Potential difference, 
Let v is the velocity of a proton that has been accelerated by a potential difference of 15 kV.
Using the conservation of energy as :

q is the charge of proton
m is the mass of proton




or

So, the velocity of a proton is
. Hence, this is the required solution.
The measure of the quantity of matter would be mass. Mass is measured in kilograms. I hope this helped!:)
The correct answer for the statement “All the scientific
theories used to explain the formation of the solar system are non-testable”. The
answers outdated, imaginative and unacceptable are wrong. These theories are
not proven and yet are not tested due to the complexity.
Acceleration = velocity / time.