Universe
Universe
11th Edition
ISBN: 9781319039448
Author: Robert Geller, Roger Freedman, William J. Kaufmann
Publisher: W. H. Freeman
bartleby

Concept explainers

Question
Book Icon
Chapter 16, Problem 13Q

(a)

To determine

The amount of the energy released by the annihilation of an electron and a positron, if a positron has the same mass as an electron.

(a)

Expert Solution
Check Mark

Answer to Problem 13Q

Solution:

1.6×1013 J

Explanation of Solution

Given data:

The mass of the electron and the positron is the same.

Formula used:

According to the mass energy equation, the relation between energy and mass is:

E=mc2

Here, E is the energy released, m is the total mass of the positron and electron, and c is the speed of light, 3×108 m/s.

Explanation:

The mass of the electron is 9.1×1031 kg and the mass of the positron is also 9.1×1031 kg.

Then, the total mass of the electron and positron is,

m=(9.1×1031 kg)+(9.1×1031 kg)=1.82×1030 kg

Recall the expression for the mass-energy equation.

E=mc2

Substitute 1.82×1030 kg for m and 3×108 m/s for c.

E=(1.82×1030 kg)(3×108 m/s)2=(1.82×1030 kg)(9×1016 kg)=1.6×1013 J

Conclusion:

Therefore, the amount of energy released by the annihilation of electron and positron is 1.6×1013 J.

(b)

To determine

The wavelength of each photon. Also, confirm from figure 5-7 (from textbook) that this wavelength falls in the range of gamma-rays, if the products of the annihilation are two photons each of equal energy.

(b)

Expert Solution
Check Mark

Answer to Problem 13Q

Solution:

0.013 arcsec

Explanation of Solution

Given data:

The products of the annihilation are two photons, each of equal energy.

Formula used:

The expression for the relationship between energy and wavelength is:

E=hcλ

Here, E is the energy received by each photon, λ is the wavelength of each photon, and h is Planck’s constant, 6.6×1034 J.s.

Explanation:

Each photon receives half of the total energy released in annihilation. So, the energy received by each photon is 8.1×1014 J.

Recall the expression for the relationship between energy and wavelength.

E=hcλ

Rearrange the above expression for λ.

λ=hcE

Substitute 8.1×1014 J for E, 6.6×1034 Js for h and 3×108 m/s for c.

λ=(6.6×1034 Js)(3×108 m/s)8.1×1013 J=2.4×1012 m(109 nm1 m)=2.4×103 nm

Refer to figure 5-7 from the textbook and determine whether the calculated wavelength 2.4×103 nm lies in the range of gamma-rays. The range of gamma rays is 0.01 nm to 10.0 nm.

Conclusion:

Therefore, this wavelength lies in the range of gamma-rays.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
suppose you collected a data set in which you measured fall-times for different fall-heights, you plotted the data and fit the mathemathical model, y=Ax^2, to match the physical hypothesis, y=0.5*g*t^2. From the best fit curve you are told that the value of your fit-parameter, A, is for 4.6 m/s^2 +/- 0.4 m/s^2. Determine the value of g +/- delta g for this fit parameter value.
Problem 2: Black hole – the ultimate blackbody A black hole emits blackbody radiation called Hawking radiation. A black hole with mass M has a total energy of Mc², a surface area of 167G²M² /c*, and a temperature of hc³/167²KGM. a) Estimate the typical wavelength of the Hawking radiation emitted by a 1 solar mass black hole (2 × 103ºkg). Compare your answer to the size of the black hole. b) Calculate the total power radiated by a one-solar mass black hole. c) Imagine a black hole in empty space, where it emits radiation but absorbs nothing. As it loses energy, its mass must decrease; one could say "evaporates". Derive a differential equation for the mass as a function of time, and solve to obtain an expression for the lifetime of a black hole in terms of its mass.
We saw that, on Earth, the number flux of solar neutrinos from the p-p chain is 6.7E10 s-1 cm-2. Other nuclear reactions in the Sun supplement this neutrino flux with a small additional flux of higher-energy neutrinos. A neutrino detector in Japan, named Super Kamiokande, consists of a tank of 50kton of water, surrounded by photomultiplier tubes. The tubes detect the flash of Cerenkov radiation emitted by a recoiling electron when a high-energy neutrino scatters on it. Calculate the detection rate for neutrino scattering in events per day, if 10-6 of the solar neutrinos have a high enough energy to be detected by this experiment, and each electron poses a scattering cross section=10-43 cm. Hint: Consider the density of neutrino targets "seen" by an individual electron, with a relative velocity of c between the neutrinos and the electron, to obtain the rate at which one electron interacts with the incoming neutrinos, and multiply by the total number of electrons (I've already done this:…
Knowledge Booster
Background pattern image
Physics
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.
Similar questions
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
College Physics
Physics
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Cengage Learning
Text book image
University Physics (14th Edition)
Physics
ISBN:9780133969290
Author:Hugh D. Young, Roger A. Freedman
Publisher:PEARSON
Text book image
Introduction To Quantum Mechanics
Physics
ISBN:9781107189638
Author:Griffiths, David J., Schroeter, Darrell F.
Publisher:Cambridge University Press
Text book image
Physics for Scientists and Engineers
Physics
ISBN:9781337553278
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Text book image
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:9780321820464
Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:Addison-Wesley
Text book image
College Physics: A Strategic Approach (4th Editio...
Physics
ISBN:9780134609034
Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:PEARSON