Question

1. The point in the Moon's orbit when it's farthest away from the Earth is called

Answer 1

1.C | 2.D | 3.B | 4.D  

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1. The point in the Moon's orbit when it's farthest away from the Earth is called apogee.  On the contrary, the perigee is the point in the Moon's orbit when it's the nearest from the Earth. Those points are very important for tides and other natural phenomenon such as eclipse and in general for the observation of the skies.

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2. Gamma rays are a type of electromagnetic radiation cannot be focused. They diffuse from the emission points until there is an object that stops them. This is the reason why when you  have to use gamma rays, you are in other rooms, in order to prevent the radiation to go through them.  

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3. The corona it's the outermost layer of the Sun's atmosphere.  It's also the part where most of the activity of the sun that we can see take places. It's a subject that has fascinating scientists for centuries and only recently we are studying in more details this interesting and weird place, due to the advancement of technology.

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4. Tides are a result of the gravitational attraction of the Sun and Moon. The Earth, the Sun and the Moon have masses and their own gravities. The interactions between these corps causes tides movement on Earth that are fundament to life on the planet, because they are a fundamental part in the cycle of water and air.  

Answer 2

Answer:

1.C

2.D

3.B

4.D

Explanation:

1. The orbit on which moon revolve around earth has a perigee point which is the nearest point to earth while apogee is the farthest point to planet earth.  

A penumbral is a region in which occluding body obscure a portion of light. It has no relation with the moon's orbit. Also an eclipse is a phase based on position of moon with respect to earth and sun

Hence, option C is correct

2. Gamma rays are extremely powerful and energetic as they are produced as a result of radiation and hence it is very difficult to focus them on normal lenses which are designed to focus only visible light. They interact with the matter of the focusing surface and destroys them selves.

Hence, option D is correct

3. Corona is the outer surface of stars  that extends to millions of kilometers into the space. Sun being a star has corona at its outer layer which is visible only during  

total solar eclipse. Hence option B is correct

4. When the gravitational force of moon attracts the water on earth, it presume a rising and falling form that is termed as tides.  

Hence option D is correct