contestada

• Most of the galaxies in the universe are moving away from
Earth. Suppose a particular galaxy emits orange light with
a frequency of 5.00 * 1014 Hz. If the galaxy is receding
from Earth with a speed of 3325 km/s, what is the
frequency of the light when it reaches Earth?
• A) 4.945 x 1014 Hz
• B) 5.542 1012 Hz
• C) 5.055 1014 Hz​

Respuesta :

The frequency of the light observed from the Earth is [tex]4.945\cdot 10^{14}Hz[/tex]

Explanation:

First of all, we start by noticing that the galaxy is receding from Earth (moving away): this means that according to the Doppler effect, the frequency of the light as seen from the Earth must be shorter than the real frequency of the light emitted by the galaxy.

Furthermore, we can quantify the change in frequency of the light using the following equation:

[tex]\frac{\Delta f}{f}=\frac{v}{c}[/tex]

where

[tex]\Delta f[/tex] is the change in frequency

f is the real frequency

v is the velocity of recession of the galaxy (negative if the galaxy is moving away)

c is the speed of light

In this problem, we have:

[tex]f=5.00\cdot 10^{14} Hz[/tex]

[tex]v=-3325 km/s = -3.325\cdot 10^6 m/s[/tex]

[tex]c=3\cdot 10^8 m/s[/tex]

Substituting and solving for [tex]\Delta f[/tex], we find

[tex]\Delta f = \frac{v}{c}f=\frac{-3.325\cdot 10^6}{3\cdot 10^8}(5.00\cdot 10^{14})=-5.542\cdot 10^{12} Hz[/tex]

And therefore, the frequency of the light observed from the Earth is

[tex]f'=f+\Delta f = 5.00\cdot 10^{14} +(-5.52\cdot 10^{12})=4.945\cdot 10^{14}Hz[/tex]

Learn more about frequency and waves:

brainly.com/question/5354733

brainly.com/question/9077368

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