Answer:
Velocity of a proton,
Step-by-step 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.