/*! 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 17 Two astronauts are \(1.5 \mathrm... [FREE SOLUTION] | 91Ó°ÊÓ

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Two astronauts are \(1.5 \mathrm{m}\) apart in their spaceship. One speaks to the other. The conversation is transmitted to earth via electromagnetic waves. The time it takes for sound waves to travel at \(343 \mathrm{m} / \mathrm{s}\) through the air between the astronauts equals the time it takes for the electromagnetic waves to travel to the earth. How far away from the earth is the spaceship?

Short Answer

Expert verified
The spaceship is approximately 1311 kilometers away from Earth.

Step by step solution

01

Calculate Time for Sound to Travel

First, determine the time it takes for sound to travel between the astronauts. Use the formula: \[ t = \frac{d}{v} \] where \( d = 1.5 \) meters and \( v = 343 \) m/s. So, \[ t = \frac{1.5}{343} \approx 0.00437 \text{ seconds} \]
02

Assume Time for Electromagnetic Waves

The time calculated for sound to travel (\(0.00437\) seconds) is the same time it takes for electromagnetic waves to travel from the spaceship to Earth.
03

Use Speed of Light to Calculate Distance

Electromagnetic waves travel at the speed of light, \( c = 3 \times 10^8 \) m/s. Use the time \( t = 0.00437 \) seconds to calculate the distance \( d \) to Earth. The formula is: \[ d = c \cdot t = 3 \times 10^8 \times 0.00437 \approx 1.311 \times 10^6 \text{ meters} \]
04

Convert Distance to Kilometers

Convert the distance from meters to kilometers by dividing by 1000: \[ d = \frac{1.311 \times 10^6}{1000} = 1311 \text{ kilometers} \]

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Key Concepts

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

Speed of Sound
The speed of sound is the rate at which sound waves travel through a medium, such as air, water, or solids. In the given problem, sound travels through the air between the astronauts at a speed of 343 meters per second (m/s). This speed can vary depending on factors like temperature, humidity, and atmospheric pressure, although 343 m/s is a standard approximation for room temperature air at sea level.

When calculating how long it takes for sound to travel a certain distance, the formula used is:
  • \( t = \frac{d}{v} \)
where \( t \) is time, \( d \) is distance (meters), and \( v \) is the velocity or speed of sound (m/s).
In simple terms, you'll divide the distance the sound travels by the speed of sound to find out how long it takes for the sound to reach its destination. In this scenario, the astronauts are only 1.5 meters apart, which results in a very short travel time of about 0.00437 seconds for sound to make that journey.
Speed of Light
Electromagnetic waves, such as those used in radio communications and light, travel at the speed of light. This is the fastest speed known in the universe, approximately 300,000,000 meters per second (3 x 10^8 m/s).

For the problem at hand:
  • The conversation between the astronauts is transmitted to Earth via electromagnetic waves.
  • These waves travel at this immense speed of light.
Knowing the speed of light allows calculations of distances or times when you know one of the other variables. Since light travels so quickly, it takes only a fraction of a second for it to cover vast distances, like from a spaceship to Earth. In this exercise, the time taken calculated for sound (0.00437 seconds) is used, along with the speed of light, to determine how far away Earth is from the spaceship.
Distance Calculation
Distance calculation is a crucial aspect of understanding how long it will take something traveling at a particular speed to reach its destination. In this context, both the speed of sound and the speed of light are used to determine the distance from the spaceship to Earth.

To find the distance the electromagnetic waves (traveling at light speed) cover in the same time it takes sound to travel between the astronauts, we use the same formula rearranged:
  • \( d = c \cdot t \)
where \( c \) is the speed of light, and \( t \) is the time (0.00437 seconds). Plugging in these values:
  • \( d = 3 \times 10^8 \text{ m/s} \cdot 0.00437 \text{ s} = 1.311 \times 10^6 \text{ meters} \)
Since we usually express such large distances in kilometers, the calculation concludes by converting meters to kilometers:
  • \( 1311 \text{ kilometers} \)
This gives us the distance from the spaceship to Earth, all using simple multiplication and unit conversion principles.

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Most popular questions from this chapter

Suppose that a police car is moving to the right at \(27 \mathrm{m} / \mathrm{s},\) while a speeder is coming up from behind at a speed of \(39 \mathrm{m} / \mathrm{s},\) both speeds being with respect to the ground. Assume that the electromagnetic wave emitted by the police car's radar gun has a frequency of \(8.0 \times 10^{9} \mathrm{Hz}\) Find the difference between the frequency of the wave that returns to the police car after reflecting from the speeder's car and the original frequency emitted by the police car.

Light that is polarized along the vertical direction is incident on a sheet of polarizing material. Only \(94 \%\) of the intensity of the light passes through the sheet and strikes a second sheet of polarizing material. No light passes through the second sheet. What angle does the transmission axis of the second sheet make with the vertical?

A politician holds a press conference that is televised live. The sound picked up by the microphone of a TV news network is broadcast via electromagnetic waves and heard by a television viewer. This viewer is seated \(2.3 \mathrm{m}\) from his television set. A reporter at the press conference is located \(4.1 \mathrm{m}\) from the politician, and the sound of the words travels directly from the celebrity's mouth, through the air, and into the reporter's ears. The reporter hears the words exactly at the same instant that the television viewer hears them. Using a value of \(343 \mathrm{m} / \mathrm{s}\) for the speed of sound, determine the maximum distance between the television set and the politician. Ignore the small distance between the politician and the microphone. In addition, assume that the only delay between what the microphone picks up and the sound being emitted by the television set is that due to the travel time of the electromagnetic waves used by the network.

In a traveling electromagnetic wave, the electric field is represented mathematically as $$ E=E_{0} \sin \left[\left(1.5 \times 10^{10} \mathrm{s}^{-1}\right) t-\left(5.0 \times 10^{1} \mathrm{m}^{-1}\right) x\right] $$ where \(E_{0}\) is the maximum field strength. This equation is an adaptation of Equation \(16.3 .\) (a) What is the frequency of the wave? (b) This wave and the wave that results from its reflection can form a standing wave, in a way similar to that in which standing waves can arise on a string (see Section 17.5 ). What is the separation between adjacent nodes in the standing wave?

An electromagnetic wave strikes a \(1.30-\mathrm{cm}^{2}\) section of wall perpendicularly. The rms value of the wave's magnetic field is determined to be \(6.80 \times 10^{-4} \mathrm{T}\). How long does it take for the wave to deliver \(1850 \mathrm{J}\) of energy to the wall?

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