How do i find the speed of a proton if the potential difference is 300 V?

Answer 1

Voltage is a measure of the energy a charged particle gains or loses in going from one place to another. Imagine that you have several hills, and a ball. If you roll the ball down hills of different heights, it will gain different amounts of kinetic energy. As gravity times height is for the hills, voltage times charge is for your problem. The units of voltage are energy per amount of charge.

Now you need to go find out exactly how much energy per charge one volt is, and how much charge is in one proton. These definitions should be somewhere in your physics book.

Answer 2

Data: speed of a proton = ?
V = 300 V
m = mass of a proton = 1.672 EXP -27 kg
q = charge of a proton = 1.6 EXP -19 C

Equation: Kinetic Energy (= Work) = charge q x potential V
KE = qV = 1/2 mv2
or v is equal to the square root of 2qV/m

Solution: v = square root of 2(1.6 EXP -19 C)(300 V)/1.672 EXP -27 kg
v = 239616.9191 m/s

Answer 3

The proton has the same charge as an electron (but opposite in sign). When accelerated through a potential of 300v, it will gain energy equal to 300 electron-volts, which is 1.6*10^-19 joules. It has a mass of 1.7*10^-27kg. Since its kinetic energy is .5mv^2, v=sqrt(2*E/m). E/m is ~10^8 joules/kg v = 1.4*10^4m/sec All of these values are in Wikipedia and any physic reference book.