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Helen [10]
3 years ago
9

explain why for thousands of years people believed that stars moved across Earth's sky. Explain why we now have a different expl

anation of why stars move across the night sky. Be sure to mention reference points.
Physics
1 answer:
Anarel [89]3 years ago
6 0

Answer:

Ptolemy proposed a model, he reference system is centered on the Earth

Copernicus, proposed a deferent system,  this system is centered on the Sun, where it is at the origin of the system

Explanation:

Thousands of years ago, Ptolemy proposed a model to explain the movement of the planets and stars in the sky, in this model the reference system is centered on the Earth, so each body is orbiting in different spheres around the Earth as its center, this system had very complicated calculations and curves to be able to explain the orbits of the planets.

More recently Copernicus, proposed a deferent system, this system is centered on the Sun, where it is at the origin of the system, in this system the movement of the planets are ellipses, which is a much simpler explanation and has been widely accepted, in current systems the reference system is fixed in the bodies more massive, since this simplifies the explanation of the movements.

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user100 [1]

The resultant displacement between the two vectors will increase.

The resultant of the two vectors is given by parallelogram law of vectors.

The parallelogram law of vector addition states that if two vectors are represented in magnitude and direction by the adjacent sides of a parallelogram, the diagonal of the parallelogram drawn from the point of intersection of the vectors represents the resultant vector in magnitude and direction.

The resultant of these vectors, say vector A, and B, is given as;

R^2 = a^2 + b^2 -2ab.Cos (\theta )

When;

θ = 90°

R^2 = a^2 + b^2

When;

θ = 120°

R^2 = a^2 + b^2 + ab

Thus, the resultant displacement between the two vectors will increase.

Learn more here: brainly.com/question/20885836

8 0
3 years ago
Which experiment best shows water’s ability to act as a solvent? raise the temperature of water and record its boiling point. fr
IrinaVladis [17]
The vanishing of an ionic solid (like table salt) would be an example of acting like a solvent
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3 years ago
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Nutka1998 [239]
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4 0
3 years ago
A 67 kg soccer player uses 5100 kJ of energy during a 2.0 h match. What is the
Oksanka [162]

The  average power produced by the soccer player is  710 Watts.

Given the data in the question;

  • Mass of the soccer player; m = 67kg
  • Energy used by the soccer player; E = 5100KJ = 5100000J
  • Time; t = 2.0h = 7200s

Power; P =\ ?

Power is simply the amount of energy converted or transferred per unit time. It is expressed as:

Power = \frac{Energy\ converted }{time}

We substitute our given values into the equation

Power = \frac{5100000J}{7200s}\\\\Power = 708.33J/s \\\\Power = 710J/s \ \ \ \ \ [ 2\ Significant\ Figures]\\\\Power = 710W

Therefore, the  average power produced by the soccer player is  710 Watts.

Learn more: brainly.com/question/20953664

8 0
2 years ago
What Molecules can be found in the interstellar medium? A. Water, Carbon dioxide, and Hydrogen. B. Oxygen, Nitrogen and ammonia.
Masteriza [31]
The interstellar medium is the matter as well as the radiations that are found in the galaxies occupying the spaces between the star systems.
Interstellar medium is mainly composed of hydrogen that is followed by helium and trace amounts of nitrogen, oxygen and carbon (considered traces when compared to amount of hydrogen).

Therefor, the right choice is:
<span>A. Water, Carbon dioxide, and Hydrogen</span>
3 0
3 years ago
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