The answer OC. It can be changed only if all scientists approve the change
Answer:
First, as you may know, the light travels at a given velocity.
In vaccum, this velocity is c = 3x10^8 m/s.
And we know that:
distance = velocity*time
Now, if some object (like a star ) is really far away, the light that comes from that star may take years to reach the Earth.
This means that the images that the astronomers see today, actually happened years and years ago (So the night sky is like a picture of the "past" of the universe)
Also, for example, if an astronomer sees some particular thing, he can apply a model (a "simplification" of some phenomena that is used to simplify it an explain it) and with the model, the scientist can infer the information of the given thing some time before it was seen.
Answer:
(A) FM Radio had a somewhat shorter ranger than AM radio, but better sound quality.
Explanation:
FM Radio was invented in 1933 by Edwin Armstrong who was an American engineer. FM stands for frequency modulation and AM stands for Amplitude Modulation.
FM is used for most broadcasts of music and FM radio stations use a very high-frequency range of radio frequencies.
In FM Radio, the sound is transmitted through changes in frequency. Both FM and AM radio signals experience frequent change in amplitude, they are far less noticeable on FM.
When switching between stations, FM antenna is alternating between different frequencies, and not amplitudes and this produces a much clearer sound and allows for smoother transitions with little to no audible static.
FM signals can be interfered by barriers and this could affect the signal strength. FM Radio signals are more clearer in a mountainous area that has no barrier.
AM radio was able to carry signals farther than AM radio.
The wavelength of the infrared radiation is λ = 
×
m.
<h3>What is infrared radiation?</h3>
An infrared telescope is tuned to detect infrared radiation with a frequency of 9.45 THz.
We know that,
1 THz = 10¹² Hz
So,
f = 9.45 × 10¹² Hz
We need to find the wavelength of the infrared radiation.
λ=c/f
λ = 3×
/9.45×
λ = 3.174 × m
The term "infrared radiation" (IR) refers to a part of the electromagnetic radiation spectrum with wavelengths between about 700 nanometers (nm) and one millimeter (mm). Longer than visible light waves but shorter than radio waves are infrared waves.
Electromagnetic radiation with wavelengths longer than those of visible light is known as infrared, also known as infrared light. Since it is undetectable to the human eye, The typical range of wavelengths considered to be infrared (IR) is from about 1 millimeter to the nominal red edge of the visible spectrum, or about 700 nanometers.
To learn more about infrared radiation from the given link:
brainly.com/question/13163856
#SPJ4
Explanation:
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