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erica [24]
3 years ago
13

Astronomers can now report that active star formation was going on at a time when the universe was only 20% as old as it is toda

y. When astronomers make such a statement, how can they know what was happening inside galaxies way back then
Physics
1 answer:
disa [49]3 years ago
8 0

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.

You might be interested in
Please help! Will give a lot of points
krek1111 [17]
Answer:

Chemical and Biological weathering.

Explanation:

Processes that break down and weaken earth minerals are known as weathering. Over time, this can lead to erosion, in which huge sections of rock and stone are carried away, changing landscapes. Physical weathering alters the material structure of rocks, while chemical weathering alters their chemical structure.
3 0
2 years ago
The number ocean waves that pass a buoy in one second is _ of the wave
mr_godi [17]
The number of ocean waves that pass a buoy in one second is the frequency of the <span>wave. The crest of a transverse wave is its highest point. </span>
7 0
3 years ago
Read 2 more answers
A net force of 50 newtons is applied to a 20 kilogram cart that is already moving at 1 m/s the final speed of the cart was 3 m/s
valina [46]

Answer:

0.8 seconds

Explanation:

F=ma

Let x be the seconds the force is applied.

m = 20kg

F = 50 Newtons (kg*m/sec^2)

acceleration, a, is provided for x seconds to increase the speed from 1 m/s to  3 m/s, an increase of 2m/s

Let's calculate the acceleration of the cart:

F=ma

(50 kg*m/s^2) = (20kg)*a

a = 2.5 m/s^2

---

The acceleration is 2.5 m/s^2.  The cart increases speed by 2.5 m/s every second.  

We want the number of seconds it takes to add 2.0 m/sec to the speed:

(2.5 m/s^2)*x = 2.0 m/s

x = (2.0/2.5) sec

x = 0.8 seconds

7 0
2 years ago
Which group of animals would be served best by the following adaptations?
aev [14]
The answer to this question would be: <span>A) animals that live in deserts 

</span>Desert temperature is high, especially in the day, <span>An animal that lives in the desert needs to adapt to the high temperature either by reducing the heat or by increasing heat loss. By becoming nocturnal, the animal also able to evade the sunlight so it was less exposed to the heat. 
Unlike other option, the desert is lacking water. Desert is mostly dry and water would be a resource that hard to find. In this case, k</span><span>idneys adapted to check water loss would be a great help</span>
5 0
3 years ago
Read 2 more answers
What is (a) the wavenumber and (b) the wavelength of the radiation used by an fm radio transmitter broadcasting at 92. 0 mhz?
yulyashka [42]

The wavenumber and (b) the wavelength of the radiation used by an fm radio transmitter broadcasting at 92. 0 mhz will be  31.25 * 10^{2} m^{-1} and 0.032 * 10^{2} m respectively

Forms of electromagnetic radiation like radio waves, light waves or infrared (heat) waves make characteristic patterns as they travel through space. Each wave has a certain shape and length. The distance between peaks (high points) is called wavelength.

Wavenumber, also called wave number, a unit of frequency, often used in atomic, molecular, and nuclear spectroscopy, equal to the true frequency divided by the speed of the wave and thus equal to the number of waves in a unit distance.

wavelength = ?

frequency = 92 m Hz = 92 * 10^{6} Hz

speed of light = 3 * 10^{8} m/s

speed of light = frequency * wavelength

wavelength = speed of light  / frequency

                     = 3 * 10^{8}  / 92 * 10^{6}

                     = 0.032 * 10^{2} m

wavenumber = 1 / wavelength

                      = 1 / 0.032 * 10^{2} m

                      = 31.25 * 10^{2} m^{-1}

To  learn more about electromagnetic radiation here

brainly.com/question/10759891

#SPJ4

5 0
1 year ago
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