Concept explainers
(a)
The speed of Earth in its orbit by using the data in appendix 1, if the Earth’s orbit is assumed to be circular.
(a)

Answer to Problem 26Q
Solution:
Explanation of Solution
Given data:
From appendix 1, the radius of the Earth’s orbit is
Formula used:
Write the expression for speed.
Here,
Explanation:
Since it is given that Earth’s orbit is to be assumed to be circular, the distance covered by the Earth in a revolution is equal to the perimeter of the circle.
Recall the expression for speed.
Substitute
Here, is the radius of Earth’s orbit.
Substitute
Conclusion:
Hence, the speed of Earth in its orbit calculated by using the data from appendix 1 is close to
(b)
The wavelength (in meters) of the signal received by the Earth if the aliens are transmitting it at a frequency of
(b)

Answer to Problem 26Q
Solution:
Explanation of Solution
Given data:
The frequency of the signal is
Formula used:
Write the expression for the wavelength of a wave.
Here,
Explanation:
Consider the speed of light to be
As the Earth is neither moving toward nor away from the alien’s planet, so there is no relative motion between the planets. Therefore, there would be no Doppler effect.
Recall the expression for the wavelength of a wave.
Substitute
Conclusion:
Thus, the wavelength of the signal received by Earth from the aliens under the given condition is calculated to be
(c)
The maximum wavelength shift in meters as well as in percentage of unshifted wavelength, calculated in part (b), if the maximum Doppler shift occurs when moving directly toward or away from the alien planet.
(c)

Answer to Problem 26Q
Solution:
Explanation of Solution
Given data:
The frequency of the signal is
Formula used:
Write the expression for the Doppler shift if the receiver is directly approaching the transmitter.
Here,
Explanation:
Since the Earth (receiver) is moving directly toward the alien planet (transmitter), there is a relative motion between them. Therefore, a Doppler shift would be observed.
Recall the value of the wavelength of the signal received by the Earth from the aliens as calculated in part (b).
Recall the value of Earth’s speed in its orbit under the given condition form part (a).
Consider the speed of light to be
Recall the expression for the Doppler shift if the receiver is directly approaching toward the transmitter.
Rearrange the expression in terms of
Substitute
The maximum wavelength shift in percentage of unshifted wavelength is given by the expression:
Here,
Substitute
Conclusion:
The maximum wavelength shifts in meters as well as in percentage of unshifted wavelength is calculated as
(d)
The reason behind the utmost importance given to the precision of the SETI radio receiver to measure frequency and wavelength.
(d)

Answer to Problem 26Q
Solution:
The Doppler shift calculated is very small
Explanation of Solution
Introduction:
Doppler Effect is defined as the phenomenon in which there is a sudden noticeable change in the pitch or wavelength when there is a relative motion between the transmitter and the receiver.
The expression for the Doppler shift if the receiver is directly approaching the transmitter is:
Here,
Explanation:
Recall the value of the maximum wavelength shift in meters, calculated in the previous part, that is, part (c).
Also recall the value of the maximum wavelength shift in percentage of unshifted wavelength.
It can be clearly observed from these two values that the wavelength of the receiving signal is very less. Therefore, to identify the Doppler shift, the SETI radio receiver must be highly precise. If the receiver is not precise and accurate, it would not detect such a small magnitude change and the signal from the alien planet would not be verified.
Conclusion:
The SETI radio receiver must be very precise to detect the very small shift in the wavelength due to Doppler effect.
Want to see more full solutions like this?
Chapter 27 Solutions
EBK LOOSE-LEAF VERSION OF UNIVERSE
- The angle between the axes of two polarizing filters is 19.0°. By how much does the second filter reduce the intensity of the light coming through the first? I = 0.106 40 xarrow_forwardAn oil slick on water is 82.3 nm thick and illuminated by white light incident perpendicular to its surface. What color does the oil appear (what is the most constructively reflected wavelength, in nanometers), given its index of refraction is 1.43? (Assume the index of refraction of water is 1.33.) wavelength color 675 × nm red (1 660 nm)arrow_forwardA 1.50 μF capacitor is charging through a 16.0 Ω resistor using a 15.0 V battery. What will be the current when the capacitor has acquired 1/4 of its maximum charge? Please explain all stepsarrow_forward
- In the circuit shown in the figure (Figure 1), the 6.0 Ω resistor is consuming energy at a rate of 24 J/s when the current through it flows as shown. What are the polarity and emf of the battery E, assuming it has negligible internal resistance? Please explain all steps. I know you need to use the loop rule, but I keep getting the answer wrong.arrow_forwardIf you connect a 1.8 F and a 2.6 F capacitor in series, what will be the equivalent capacitance?arrow_forwardSuppose that a particular heart defibrillator uses a 1.5 x 10-5 Farad capacitor. If it is charged up to a voltage of 7300 volts, how much energy is stored in the capacitor? Give your answer as the number of Joules.arrow_forward
- The voltage difference across an 8.3 nanometer thick cell membrane is 6.5 x 10-5volts. What is the magnitude of the electric field inside this cell membrane? (Assume the field is uniform, and give your answer as the number of Volts per meter... which is the same as the number of Newtons per Coulomb.)arrow_forwardThree identical capacitors are connected in parallel. When this parallel assembly of capacitors is connected to a 12 volt battery, a total of 3.1 x 10-5 coulombs flows through the battery. What is the capacitance of one individual capacitor? (Give your answer as the number of Farads.)arrow_forwardSuppose you construct your own capacitor by placing two parallel plates at a distance 0.27 meters apart. The plates each have a surface area of 0.64 square meters. What is the capacitance of this setup? (Give your answer as the number of Farads.)arrow_forward
- Draw a diagram with the new arrows. No they do not point all towards the center.arrow_forwardExample In Canada, the Earth has B = 0.5 mŢ, pointing north, 70.0° below the horizontal. a) Find the magnetic force on an oxygen ion (O2) moving due east at 250 m/s b) Compare the |FB| to |FE| due to Earth's fair- weather electric field (150 V/m downward).arrow_forwardFour charges, qa, qb, qa, and qd are fixed at the corners of a square. A charge q that is free to move located at the exact center of the square. Classify the scenarios described according to the force that would be exerted on the center charge q. Assume in each case that q is a positive charge. Do not assume that the fixed charges have equal magnitudes unless the scenario defines such an equality. qa Яс q %b Force is zero Force is to the left Force is to the right Force is undeterminedarrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningStars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage Learning
- AstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStaxFoundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning





