# Annihilation of electron and positron

• ehabmozart
In summary, the question asks for the average energy of two gamma photons produced when a positron with kinetic energy 2.2MeV collides with an electron at rest and annihilates. The solution involves including the rest masses in the calculation and dividing by 2 to find the average energy. The original poster also mentions another question they need help with, which can be found at the provided link.
ehabmozart

## Homework Statement

A positron with kinetic energy 2.2MeV collides with an electron at rest, and annihilate each other.
a. Calculate the average energy of the two gamma photons produced as a result of annihilation

## The Attempt at a Solution

I would infact calculate the energy in the left hand side including the rest masses.. isn't it.. So it would be (0.511 x 2) + 2.2 = 3.222 MeV .. But this doesn't seem the answer.. Any help guys?

hi ehabmozart!
ehabmozart said:
A positron with kinetic energy 2.2MeV collides with an electron at rest, and annihilate each other.
a. Calculate the average energy of the two gamma photons produced as a result of annihilation

I would infact calculate the energy in the left hand side including the rest masses.. isn't it.. So it would be (0.511 x 2) + 2.2 = 3.222 MeV .. But this doesn't seem the answer.. Any help guys?

maybe they want you to divide by 2, for the average?

Thanks.. I guess this gave me the answer... Dude, i will owe u if u just solve the question in this link.. Drivin' me crazy and no replies till now

## 1. What is the process of annihilation of an electron and a positron?

The annihilation of an electron and a positron is a process where the two particles collide and their masses are converted into energy in the form of photons.

## 2. How does the annihilation of an electron and a positron occur?

The annihilation of an electron and a positron occurs when they come into contact with each other and their opposite charges cancel out, resulting in the conversion of their masses into energy.

## 3. What happens to the energy produced during the annihilation of an electron and a positron?

The energy produced during the annihilation of an electron and a positron is released in the form of photons, which can then be detected and measured.

## 4. Can the annihilation of an electron and a positron occur spontaneously?

No, the annihilation of an electron and a positron can only occur when they come into contact with each other, as they are both stable particles and do not decay on their own.

## 5. What are some applications of electron-positron annihilation in science?

Electron-positron annihilation is used in particle accelerators to study subatomic particles and in medical imaging techniques such as positron emission tomography (PET) scans to detect and diagnose diseases.

• Introductory Physics Homework Help
Replies
5
Views
1K
• High Energy, Nuclear, Particle Physics
Replies
5
Views
666
• Other Physics Topics
Replies
5
Views
1K
• Introductory Physics Homework Help
Replies
1
Views
964
• Quantum Physics
Replies
23
Views
2K
• High Energy, Nuclear, Particle Physics
Replies
0
Views
1K
• Introductory Physics Homework Help
Replies
1
Views
2K
• Introductory Physics Homework Help
Replies
12
Views
303
• High Energy, Nuclear, Particle Physics
Replies
8
Views
1K
• Introductory Physics Homework Help
Replies
3
Views
2K