I think maybe C. a light bulb. Hope this helps :)
The right answer would be
-20t+ 80
Answer:
Option (B)
Explanation:
To measure the distance between two objects we use the units of length.
To measure small distances we use, mm or cm or m. But if we measure large distances between two objects we use large units such that kilometer or miles.
To measure the very large distances between two objects we use large units such as Astronomical unit or Parsec.
The Astronomical unit is defied as the distance between earth and Sun.
Thus, the distance between earth and the sun is defined as 1 Astronomical unit.
1 Astronomical unit = 1 A.U. = 1.5 x 10^8 km = 1.5 x 10^11 m
True, it can be seen from Earth at times
Answer:
The distance between the earth and the star is increasing.
Explanation:
When we observe an object and its electromagnetic radiation has been displaced to blue, it means that it is getting closer to us, causing the light waves it emits to get closer together and its wavelength to decrease towards blue, this is knowm as blueshift.
On the contrary, when an object is rapidly moving away from us, the light waves or electromagnetic radiation it emits have been stretched from their normal wavelength to a longer wavelength, towards the red part of the spectrum. This is known as redshift.
This phenomenon of changes in wavelength and frequency due to movement (whether the source approaches or moves away) is described by the Doppler effect.
So for this case because the light we perceive from the star has moved to the red part of the visible spectrum, we can conclude that it is moving away from the earth, and that the distance between the star and the earth is increasing.