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3 years ago

What evidence is there that the universe is expanding?

2 answers:

7 0

The main evidence is the redshift of galaxies. This means the other galaxies are moving away from us. The Andromeda galaxy is having a blueshift though, meaning it's coming closer. Another piece of evidence is warmth in space.
Hope this helps.

aksik [14]3 years ago

6 0

Answer:

Galaxies moving apart from each other.

Explanation:

It has been observed that the galaxies are moving away from each other. This expansion is an outcome of the Big Bang theory of Universe formation. The observational proof of this is the Redshift observed in the spectrum of faraway galaxies which means that they are moving away. Also, as per Hubble Law, the galaxies which are farther away from us are moving faster as compared to the ones which are closer.

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What is t = 0 s and t = 8 s?

Deffense [45]

Answer:

t=0 is t

t=8= 8t

Explanation:

because 0 is means "nothing" so that's why t=0 is t

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3 years ago

When velocity is graphed with respect to time, what does the area under

Juliette [100K]

Answer:

the answer is D

Explanation:

Since the velocity of the object is the derivative of the position graph, the area under the line in the velocity vs. time graph is the displacement of the object.

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3 years ago

Read 2 more answers

Si un cuerpo se encuentra en reposo tiene energía cinética?¿por qué?

posledela

Answer:

This is because, when an object which has possessed kinetic energy under its being in motion hits another object, which is stationary the object at rest receives part of the energy inherent in the body which has kinetic energy and expresses the received energy in the form of motion or some forms different from the initial stationary position.

Explanation:

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4 years ago

You decide it is time to clean your pool since summer is quickly approaching. Your pool maintenance guide specifies that the chl

kotykmax [81]

Answer:

Concentration of Cl2: 1,048 ppm

Explanation:

The unit of measurement molarity (M) represents the same magnitud as mole/L (number of moles of the substance in one liter of solution). The concentration in ppm represents the same as mg/L (number of miligrammes of the substance in one liter of solution). In order to convert from M to ppm we have to consider, then, mass and volume. We can see that in both cases the volume is expressed in liters, so we don't have to do anything to change it. The problem comes when you see that you have to convert moles, from the molatiry, to miligrammes, to get the result in mg/L, meaning ppm.

First of all, notice that the substance is Cl2, so we need to find a relationship between the number of moles and its mass. If you look in the periodic table you'll see that the atomic mass for Cl is 35,4 g/mole (grammes of Cl in one mole). So, there is a way to relate the moles to the mass of the substance and it is represented on the equation below:

$mass=mole*atomic mass$

We want to find the mass (m) and we know the amount of moles of Cl2 in the solution (moles=2,96x10^-5), so, if we use the values known on the equation above we get that:

$m=2,96x10^-5 moles*35,4 g/mole\\ m=1,048x10^-3 g$

Remember that these grammes are found in one liter of solution. So, this means we have 1,048x10^-3 g/L. Previously we said that ppm=mg/L, so all that's left to do it to convert grammes to miligrammes:

1 g = 1000 mg

If we multiply both sides by 1,048x10^-3:

1 * 1,048x10^-3 g = 1000 * 1,048x10^-3 mg

1,048x10^-3 g = 1,048 mg

Knowing that this amount of mass was found in one liter, we get that the amount of substance in the solution is:

1,048 mg/L

Knowing that <em>mg/L=ppm</em>, then the concentration of Cl2 in ppm is:

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3 years ago

A 1500-kg car traveling east with a speed of 25.0 m/s collides at an intersection with a 2500-kg van traveling north at a speed

IgorC [24]

Answer: