Final answer:
To bring the alpha particle to a stop, a potential difference of 250 V is applied. Using the equation for final voltage, we can find that the initial speed of the alpha particle is approximately 6.25 x 10^6 m/s.
Step-by-step explanation:
An alpha particle is made up of 2 protons and 2 neutrons. In order to bring the alpha particle to a stop, a potential difference of 250 V is applied. To find its initial speed, we can use the equation:
Final voltage = Initial voltage + (initial speed * charged particle * electric field intensity)
Substituting the given values, we have:
250 V = 0 V + (initial speed * 2) * (1.6 x 10^-19 C)
Simplifying, we find that the initial speed of the alpha particle is approximately 6.25 x 10^6 m/s.