That could be a comet, or any one of the billions of meteoroids
moving in a cloud that's actually the remains of a shattered comet.
Explanation:
The given data is as follows.
m = 5000 kg, h = 800 km = 
, r = R + h = 
kg, G = 
As we know that,

v = 
And, it is known that formula to calculate angular velocity is as follows.

v = 
= 
= 
Thus, we can conclude that speed of the satellite is
.
Answer:
1. Luminosity
2.Apparent brightness
Explanation:
There are two factors on which brightness of star appear to be in the sky
The two factors are
1. Luminosity
2.Apparent brightness
1.Luminosity :It is defined as the total energy emitted by the object in a given time.Luminosity vary with the distance of observer from the star.Luminosity is a intrinsic property which depends on the fundamental chemical composition and structure of the material.Luminosity is depends on the size of star.Lager the star luminosity will be more.
2.Apparent brightness: It is defined as how bright a star appears from an observer on the earth and the amount of starlight reaching the earth.if the distance is large then the brightness decreases.When the distance of star from us small then the brightness of star increases.Distance is inversely proportional to brightness of the star.
The arrows always start at the magnet's north pole and point towards its south pole. When two like-poles point together, the arrows from the two magnets point in OPPOSITE directions and the field lines cannot join up. So the magnets will push apart
Not possible. The air is actually able to travel sound throughout itself without any difficulties. I believe, air actually brings sound closer to the people farther away ; It really helps to stretch sound.