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kakasveta [241]
3 years ago
11

What are the historical solar system models. Differences

Physics
1 answer:
Rasek [7]3 years ago
7 0
Aristarchus(310-230 BC)
Aristarchus was a Greek Astronomer and Mathematician. He proposed the heliocentric model of the Solar System. He attempted to measure the distances from the moon to the sun.
Aristotle (334-322 BC)
<span>Aristotle was a Greek Philosopher. He was the first person to propose this historical model. He thought the Earth was in the center of all celestial beings. His idea was that the Earth was in the middle of the sun, moon, stars, and other planets. </span>
Ptolemy(100-170 CE)
<span>Ptolemy was a astronomer and a geographer and a mathematician! He proposed the geocentric model. He believed that a celestial body could go at a constant speed in a perfect circle. It was called the "wheels-on-wheels" system. It had better observations than the model that had came before his. His geocentric model was used for the next 14 centuries! </span>
Kepler(1571-1630)
<span>German astronomer and mathematician, Johannes Kepler, studied very hard and closely, and he found out that the planets did not fit the observations that were made by previous explorers. He found one that fit the best out of them all! He found three principles, called Kepler's Laws. </span>
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A _____ is a device that multiplies force or increases speed and makes work easier.
max2010maxim [7]
Machine is the answer :)
4 0
3 years ago
Read 2 more answers
Atom X contains seven protons and seven neutrons. atom Z contains seven protons and eight neutrons. which of the following state
stiks02 [169]

Answer:

The correct answer is option A: they are isotopes.

Explanation:

From atom X we know that the number of protons is 7 and the number of neutrons is 7 and from atom Z we know that the number of protons is 7 and the number of neutrons is 8.

Since the number of protons of atom X and atom Z is the same, we have that atom X and atom Z is the same element. The difference in the number of neutrons tells us that atom X and atom Z are isotopes. Remember that an isotope is one element that has atoms with different numbers of neutrons.            

The mass number is given by:              

A = p + n

Where <em>n</em> is the number of neutrons and <em>p </em>is the number of protons.

For atom X and atom Z we have:

A_{x} = 7 + 7 = 14

A_{z} = 7 + 8 = 15

Hence, they have a different mass number.  

We know that the element with 7 protons is nitrogen. The first isotope is ^{14}_{7}N and the second isotope is ^{15}_{7}N. Both isotopes are stables (they are not radioactive).  

Therefore, the correct answer is option A: they are isotopes.

I hope it helps you!                                                          

3 0
3 years ago
What are close-toed shoes least likely to provide protection against?
Dennis_Churaev [7]
Hydrogen gas is harmless to your feet so since you don’t need protection against it that seems the best answer.
8 0
3 years ago
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A projectile is fired with an initial velocity of 120.0 meters per second at an angle, θ above the horizontal. If the projectile
k0ka [10]

Answer:

θ = 62.72°

Explanation:

The projectile describes a parabolic path:

The parabolic movement results from the composition of a uniform rectilinear motion (horizontal ) and a uniformly accelerated rectilinear motion of upward or downward motion (vertical ).

The equation of uniform rectilinear motion (horizontal ) for the x axis is :

x = x₀+ vx*t   Formula (1)

vx = v₀x

Where:  

x: horizontal position in meters (m)

x₀: initial horizontal position in meters (m)

t : time (s)

vx: horizontal velocity  in m/s

v₀x: Initial speed in x  in m/s

The equations of uniformly accelerated rectilinear motion of upward (vertical ) for the y axis  are:

y= y₀+(v₀y)*t - (1/2)*g*t² Formula (2)

vfy= v₀y -gt Formula (3)

Where:  

y: vertical position in meters (m)  

y₀ : initial vertical position in meters (m)  

t : time in seconds (s)

v₀y: initial  vertical velocity  in m/s  

vfy: final  vertical velocity  in m/s  

g: acceleration due to gravity in m/s²

Data

v₀ = 120 m/s  , at an angle  θ above the horizontal

v₀x= 55 m/s

x-y components of the initial  velocity ( v₀)

v₀x = v₀*cosθ Equation (1)

v₀y = v₀*sinθ   Equation (2)

Calculating of the angle θ

We replace data in the  Equation (1)

55 =  120*cosθ

cosθ = 55 / 120

\theta = cos^{-1}(  \frac{55}{120} )

θ = 62.72°

3 0
3 years ago
(a) If a long rope is hung from a ceiling and waves are sent. up the rope from its lower end, why does the speed of the waves ch
vazorg [7]

My response to question (a) and (b) is that all of the element of the rope need to  aid or support the weight of the rope and as such, the tension will tend to increase along with height.

Note that It increases linearly, if the rope is one that do not stretch. So, the wave speed v= √ T/μ   increases with height.

<h3>How does tension affect the speed of a wave in a rope?</h3>

The Increase of the tension placed on a string is one that tends to increases the speed of a wave, which in turn also increases the frequency of any given length.

Therefore,  My response to question (a) and (b) is that all of the element of the rope need to  aid or support the weight of the rope and as such, the tension will tend to increase along with height.  Note that It increases linearly, if the rope is one that do not stretch. So, the wave speed v= √ T/μ   increases with height.

Learn more about tension from

brainly.com/question/2008782

#SPJ4

See full question below

(a) If a long rope is hung from a ceiling and waves are sent up the rope from its lower end, why does the speed of the waves change as they ascend? (b) Does the speed of the ascending waves increase or decrease? Explain.

4 0
2 years ago
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