# Clarification on electric potential and kinetic energy

• Metalsonic75
In summary, beta decay is a type of nuclear radiation in which a neutron changes into a proton, an electron, and a neutrino. This change can happen in the nucleus of an atom, with the neutron remaining in the nucleus while the electron and neutrino are ejected. One example of beta decay is the isotope 3H, which decays to 3He, with an ejected electron and neutrino. The question posed is about the minimum initial velocity of an electron starting at the surface of a helium nucleus and escaping to infinity.
Metalsonic75
One form of nuclear radiation, beta decay, occurs when a neutron changes into a proton, an electron, and a chargeless particle called a neutrino: n -> (p+) + (e-) + tex]\upsilon[/tex] where nu is the symbol for a neutrino. When this change happens to a neutron within the nucleus of an atom, the proton remains behind in the nucleus while the electron and neutrino are ejected from the nucleus. The ejected electron is called a beta particle. One nucleus that exhibits beta decay is the isotope of hydrogen ^{3}H, called tritium, whose nucleus consists of one proton (making it hydrogen) and two neutrons (giving tritium an atomic mass m = 3u Tritium is radioactive, and it decays to a helium ion: 3H -> 3He + (e-) + tex]\upsilon[/tex].

The nuclei of both 3H and 3He have radii of 1.5 *10^-15 With what velocity must the electron be ejected if it is to escape from the nucleus and not fall back?

I don't quite understand what this question is asking, but given the information (and given that neutrons have no charge) I treated this problem as if there were only two particles: the proton (nucleus) and the electron being ejected. I am unsure if this is the right setup, because of the '3' in front of the 3H and 3He.

I am also unsure of how to calculate this, because the equations we have learned imply that the force acting on a charge is only zero at a "very large distance", ie, the distance is approaching infinity. In theory this means that there is no point where the electron would not be influenced by the proton's force. So how does it escape?

I would really appreciate it if someone could give me a nudge in the right direction.

"Escape" means go to infinity.

The problem is asking this: An electron starts at the surface of a helium nucleus and escapes to infinity. What is its minimum initial velocity?

Got it!

## 1. What is electric potential?

Electric potential is the amount of electric potential energy per unit charge at a certain point in an electric field. It is measured in volts (V).

## 2. How is electric potential different from electric potential energy?

Electric potential is a property of a point in an electric field, while electric potential energy is the amount of energy that a charged particle has due to its position in an electric field.

## 3. What is the relationship between electric potential and electric potential energy?

The relationship between electric potential and electric potential energy is that electric potential energy is equal to the charge of a particle multiplied by the electric potential at that point.

## 4. How is kinetic energy related to electric potential and electric potential energy?

Kinetic energy is not directly related to electric potential and electric potential energy. However, when a charged particle moves through an electric field, its potential energy may be converted into kinetic energy, causing the particle to accelerate.

## 5. Can electric potential and electric potential energy be negative?

Yes, both electric potential and electric potential energy can be negative. This indicates that the particle has a negative charge and is moving in the opposite direction of the electric field.

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