/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 57 Quasars are thought to be the nu... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Quasars are thought to be the nuclei of active galaxies in the early stages of their formation. A typical quasar radiates energy at the rate of \(10^{41} \mathrm{~W}\). At what rate is the mass of this quasar being reduced to supply this energy? Express your answer in solar mass units per year, where one solar mass unit (1 smu \(=2.0 \times 10^{30} \mathrm{~kg}\) ) is the mass of our Sun.

Short Answer

Expert verified
The mass of the quasar is reduced at a rate of 17.48 smu/year.

Step by step solution

01

Understanding the Problem

We need to find the rate at which the mass of a quasar is reduced to supply its energy output of \(10^{41} \text{ W}\). This involves using the relation between energy, mass, and speed of light from Albert Einstein's equation \(E=mc^2\).
02

Applying Einstein's Mass-Energy Equivalence

The energy radiated by the quasar per second is given by its power output \(P = 10^{41} \text{ W}\). According to Einstein's equation \(E = mc^2\), the rate of mass loss \(\frac{dm}{dt}\) in kg/s can be calculated as follows: \[ P = \frac{dm}{dt} c^2 \] where \(c = 3 \times 10^8 \text{ m/s}\) is the speed of light.
03

Solving for Mass Loss Rate in kg/s

Rearrange the equation to solve for \(\frac{dm}{dt}\): \[ \frac{dm}{dt} = \frac{P}{c^2} = \frac{10^{41} \text{ W}}{(3 \times 10^8 \text{ m/s})^2} \] Calculating this gives \[ \frac{dm}{dt} = \frac{10^{41}}{9 \times 10^{16}} = 1.11 \times 10^{24} \text{ kg/s} \].
04

Converting Mass Loss Rate to Solar Mass Units Per Year

One solar mass unit (1 smu) is \(2.0 \times 10^{30} \text{ kg}\). We need to convert the mass loss rate from kg/s to smu/year. Start by converting \(1.11 \times 10^{24} \text{ kg/s}\) to kg/year: \[ \frac{dm}{dt} \times \text{seconds in a year} = 1.11 \times 10^{24} \times 3.15 \times 10^7 = 3.4965 \times 10^{31} \text{ kg/year} \]. Then, convert this to smu/year: \[ \frac{3.4965 \times 10^{31}}{2.0 \times 10^{30}} = 17.48 \text{ smu/year} \].

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

mass-energy equivalence
Mass-energy equivalence is a fundamental principle in physics that tells us how energy and mass are related to each other. Albert Einstein introduced this concept through his famous equation, \(E=mc^2\). This equation shows that mass can be converted into energy and vice versa.
This means that a small amount of mass can be converted into a large amount of energy, because the speed of light squared \((c^2)\) is a very large number. Understanding this concept helps us see how quasars, like the one in our problem, can radiate massive amounts of energy by converting their mass into energy.
  • \(E\) stands for energy.
  • \(m\) stands for mass.
  • \(c\) is the speed of light \((3 \times 10^8 \text{ m/s})\).
By using this equation, we can calculate how much mass a quasar loses as it emits such enormous amounts of energy.
active galaxies
Active galaxies are special kinds of galaxies that emit more energy than regular galaxies, often due to supermassive black holes at their centers. These black holes consume surrounding material, releasing large amounts of radiation. Quasars are the most energetic active galaxies, seen particularly in the early universe.
They outshine entire galaxies with the energy they produce. While these events are distant, studying them helps us understand cosmic evolution and the life cycles of galaxies. We think of quasars as the hungry, energetic centers of these early active galaxies. They help us piece together what our universe might have looked like billions of years ago.
solar mass unit
The solar mass unit (smu) is a measure of mass equivalent to the mass of our Sun. One solar mass unit is approximately \(2.0 \times 10^{30} \text{ kg}\). This unit helps astronomers and astrophysicists to easily express and compare celestial masses, especially when talking about enormous objects like stars, black holes, and quasars.
In our exercise, converting the quasar's mass loss rate to solar mass units per year makes it easier to grasp the scale of mass being converted into energy. The solar mass unit gives a more intuitive sense of the magnitude of cosmic phenomena compared to using kilograms alone, making it easier to comprehend these astronomical figures.
Remember that when we talk about cosmic scales, even a tiny fraction of a solar mass is hugely significant.
speed of light
The speed of light, denoted by \(c\), is one of the universe's fundamental constants and plays a crucial role in physics, particularly in the equation \(E=mc^2\) for mass-energy equivalence. Its value is approximately \(3 \times 10^8 \text{ meters per second}\).
Light travels fast, but not infinitely fast. It sets the ultimate speed limit of the universe. No known matter can exceed this speed. This constant helps determine how quickly information and energy can travel through space. In the context of quasars and their energy emissions, \(c^2\) indicates the amount of energy generated by a unit mass.
Understanding the speed of light and its implications helps us decipher many cosmic processes, such as how quickly a quasar can convert its mass into energy. It is an indispensable piece of the puzzle in unveiling the mysteries of our universe.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Go As you read this page (on paper or monitor screen), a cosmic ray proton passes along the left-right width of the page with relative speed \(v\) and a total energy of \(14.24 \mathrm{~nJ}\). According to your measurements, that left-right width is \(21.0 \mathrm{~cm} .\) (a) What is the width according to the proton's reference frame? How much time did the passage take according to (b) your frame and (c) the proton's frame?

A space traveler takes off from Earth and moves at speed \(0.9900 c\) toward the star Vega, which is \(26.00\) ly distant. How much time will have elapsed by Earth clocks (a) when the traveler reaches Vega and (b) when Earth observers receive word from the traveler that she has arrived? (c) How much older will Earth observers calculate the traveler to be (measured from her frame) when she reaches Vega than she was when she started the trip?

To four significant figures, find the following when the kinetic energy is \(10.00 \mathrm{MeV}\) : (a) \(\gamma\) and (b) \(\beta\) for an electron \(\left(E_{0}=0.510998\right.\) \(\mathrm{MeV}\) ), (c) \(\gamma\) and (d) \(\beta\) for a proton \(\left(E_{0}=938.272 \mathrm{MeV}\right)\), and (e) \(\gamma\) and (f) \(\beta\) for an \(\alpha\) particle \(\left(E_{0}=3727.40 \mathrm{MeV}\right)\).

To eight significant figures, what is speed parameter \(\beta\) if the Lorentz factor \(\gamma\) is \(\begin{array}{lll}\text { (a) } 1.010 & 000 & 0, \text { (b) } & 10.000000, & \text { (c) } 100.00000 \text { , }\end{array}\) and (d) \(1000.0000\) ?

In a high-energy collision between a cosmic-ray particle and a particle near the top of Earth's atmosphere, \(120 \mathrm{~km}\) above sea level, a pion is created. The pion has a total energy \(E\) of \(1.35 \times 10^{5}\) \(\mathrm{MeV}\) and is traveling vertically downward. In the pion's rest frame, the pion decays \(35.0 \mathrm{~ns}\) after its creation. At what altitude above sea level, as measured from Earth's reference frame, does the decay occur? The rest energy of a pion is \(139.6 \mathrm{MeV}\).

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.