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Sonja [21]
3 years ago
12

What is a galaxy? How many galaxies are there and how many stars does each galaxy hold?

Physics
1 answer:
Wittaler [7]3 years ago
8 0
A galaxy is a large system of stars, remnants of dead stars, dust,
interstellar gas, and dark matter, all related to each other by gravity.

Within the part of the universe that we can observe, it's estimated that
there may be as many as two trillion galaxies !

Galaxies come in all sizes.  Tiny shrimp galaxies hold no more than
a few billion stars.  Really big galaxies may hold 100 trillion stars. ( ! ! )

The galaxy we live in (the "Milky Way") is somewhere in the middle.
It's very hard to estimate the number of stars in it, because we can't
get outside of it and look it over.  Estimates of the number of stars in
our galaxy range from 100 billion to 400 billion stars. ( ! ! ! )
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CAN SOMEONE PLEASE HELP ME WITH MY PHYSICS QUESTIONS? I NEED CORRECT ANSWERS ONLY!
BARSIC [14]
<h2>Right answer: acceleration due to gravity is always the same </h2><h2 />

According to the experiments done and currently verified, in vacuum (this means there is not air or any fluid), all objects in free fall experience the same acceleration, which is <u>the acceleration of gravity</u>.  

Now, in this case we are on Earth, so the gravity value is 9.8\frac{m}{s^{2}}  

Note the objects experience the acceleration of gravity regardless of their mass.

Nevertheless, on Earth we have air, hence <u>air resistance</u>, so the afirmation <em>"Free fall is a situation in which the only force acting upon an object is gravity" </em>is not completely  true on Earth, unless the following condition is fulfiled:

If the air resistance is <u>too small</u> that we can approximate it to <u>zero</u> in the calculations, then in free fall the objects will accelerate downwards at 9.8\frac{m}{s^{2}} and hit the ground at approximately the same time.  


5 0
4 years ago
Stored energy is_____ Energy.
inn [45]
1: B

2:B
They are both Potential energy the second one can be kinetic energy if the energy flow your welcome
7 0
3 years ago
A teacher applles a force to a wall and becomes axhausted.<br> Explanation:
Finger [1]
Because they are using all of there energy to apply the force

Hope this helps — xoxo
3 0
3 years ago
What causes earthquakes? <br><br><br>Where do earthquakes begin?
Alexandra [31]

The "mantle," or layer of the earth under the crust, is composed of hot, molten rock. The temperature of the molten rock in the mantle is not consistent since it is less hot at the surface ("crust") and more hot towards the core as you move closer to the earth's center ("core").

The hotter molten rock near the core is "bigger"—less dense—than the colder rock near the crust because heat causes stuff to expand. As a result, the hotter (lighter) rock in the core tends to rise while the more dense (heavier) rock farther up tends to sink. As a result, the mantle's molten rock is in motion. It descends from the surface down into the middle, where it heats up, expands, rises back to the surface, then cools down and sinks once again. Convection currents are the patterns of molten rock movement in the mantle. The mantle's convection currents take the shape of circular patterns, causing sideways motion in addition to up and down motion.

The crust of the planet is divided into what are referred to as "plates" at its outermost point. These plates are floating on the mantle, but due to the mantle's sideways motion caused by convection currents, the plates floating on top also desire to move. This plate-moving force is also responsible for the formation of mountain ranges and earthquakes. One plate may be attempting to travel in a different direction from the other plate if there are limits between them. They might be advancing on one another, retreating from one another, or gliding past one another.

Mountain ranges are gradually formed when two plates move nearer one another. Oceans are low basins that are gradually formed as a result of two plates sliding apart from one another. Additionally, earthquake faults like the San Andreas fault in California are created when two plates jostle against one another.

An earthquake is a phenomena that causes the earth's surface to suddenly shift, either as a result of volcanic activity or the release of energy that has built up in a fault.

The definition makes it clear that the majority of earthquakes take place near plate borders, which are the intersections of two tectonic plates. Most earthquakes happen in a seismic zone called the Pacific Ring of Fire. As a result of the collision of two tectonic plates, the Ring of Fire is home to around 81 percent of the greatest earthquakes ever recorded. Additionally, here is where the majority of volcanic activity takes place. The epicenter is the point on the earth's surface that is directly above the hypocenter, which is where the earthquake begins under the surface. Foreshocks can occur during an earthquake.

7 0
2 years ago
Read 2 more answers
HELPPPPPPP !!!!!! PLS A 0.050 kg Truck moving right at 0.20 m/s collides with a toy race car weighing 0.015 kg initially at rest
sergejj [24]

Answer:

v_f=0.15\:\mathrm{m/s}

Explanation:

From the Law of Conservation of Momentum, we can write the following equation:

m_1v_1+m_2v_2=m_fv_f

Because the toy car was initially at rest, m_2v_2=0.

Therefore, we can plug in given values and solve for v_f:

m_1v_1=m_fv_f,\\0.050\cdot 0.20 = (0.050+0.015)v_f,\\v_f=\fbox{$0.15\:\mathrm{m/s}$} (two significant figures).

6 0
3 years ago
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