Answer:
the speed of the proton is

Step-by-step explanation:
Generally Electric potential energy resulting from a proton can be mathematically represented as

Where
R is the radius of the disc which is given as

q is the charge on the proton with a value of

the mass of this proton has a value of

z is the distance of the center of the disk from the question



According the law of conservation of energy
The change in kinetic energy of the proton + change in electrostatic = 0
potential energy
The change in kinetic energy is

Since u = 0 the equation becomes
change in electrostatic potential energy is

Substituting this into the equation we have
Recalling that
we have
Substituting values

Making v the subject

