University Physics Volume 3

17th Edition
William Moebs + 1 other
ISBN: 9781938168185

University Physics Volume 3

17th Edition
William Moebs + 1 other
ISBN: 9781938168185
Textbook Problem

(a) A panicle and its antiparticle are at rest relative to an observer and annihilate (completely destroying both masses), creating two y rays of equal energy. What is the characteristic y -ray energy you would look for if searching for evidence of proton-antiproton annihilation? (The fact that such radiation is rarely observed is evidence that there is very little antimatter in the universe.) (b) How does this compare with the 0.511-MeV energy associated with electron-positron annihilation?

To determine


The characteristic γ - ray energy that will be produced after proton-antiproton annihilation.



A particle and anti particle annihilate and produced two γ - rays.

Formula used:

When a proton and antiproton annihilate each other, their masses are completely destroyed and transformed into energy. This energy can be calculated using the equation,

  E=mc2, where m is the mass of the proton (or antiproton) and c is the speed of light.


When proton-antiproton annihilation occurs, both particles completely lose their mass and produce two γ - rays. Each γ -ray will have the same amount of energy, which can be calculated by,


We know, the mass of the proton ( m ) = 1.672×1027 kg, and speed of light ( c ) = 3×108 m/s

To determine


The comparison between 939 MeV of γ - ray energy produced by proton-antiproton annihilation, with the 0.511 MeV energy produced by electron-positron annihilation.

Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started

Additional Science Solutions

Find more solutions based on key concepts

Show solutions add

As shown in Figure P17.27, water is pumped into a tall, vertical cylinder at a volume flow rate R. The radius o...

Physics for Scientists and Engineers, Technology Update (No access codes included)

7-25 Write equilibrium expressions for these reactions. (a) (b) (c)

Introduction to General, Organic and Biochemistry

Does the great hydrostatic pressure of the seabed crush organisms?

Oceanography: An Invitation To Marine Science, Loose-leaf Versin

What are sister chromatids?

Human Heredity: Principles and Issues (MindTap Course List)

A genetically engineered rice variety in existence today supplies sufficient beta-carotene to fight vitamin A d...

Nutrition: Concepts and Controversies - Standalone book (MindTap Course List)