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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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Answer:

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Explanation:

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2 years ago
The bolts on a car wheel require tightening to a torque of 4 N*m. If a 9 cm long wrench is used, what is the magnitude of the fo
notsponge [240]

Answer:

320N

Explanation:

The magnitude of the torque required is expressed using the formula;

T = Fr sin theta where;

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Substitute the given values and get F

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F = 4/0.0125

F = 320N

Hence the magnitude of the force required when the force is applied at 8 degrees to the wrench is 320N

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2 years ago
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3 years ago
A wave that can travel with or without a medium is called a(n)
denis23 [38]

Answer:

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3 years ago
a 10kg cement block horizontally at 6 m/s plows into a bank of sand and comes to a stop in 2.0 m/s. What is the average impact f
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