Answer:
nothing moves if anything other doesn't move it.
natural position of things is the resting
Explanation:
yeah that's it
Answer:
is reflected back into the region of higher index
Explanation:
Total internal reflection is a phenomenon that occurs when all the light passing from a region of higher index of refraction to a region of lower index is reflected back into the region of higher index.
According to Snell's law, refraction of ligth is described by the equation

where
n1 is the refractive index of the first medium
n2 is the refractive index of the second medium
is the angle of incidence (in the first medium)
is the angle of refraction (in the second medium)
Let's now consider a situation in which

so light is moving from a medium with higher index to a medium with lower index. We can re-write the equation as

Where
is a number greater than 1. This means that above a certain value of the angle of incidence
, the term on the right can become greater than 1. So this would mean

But this is not possible (the sine cannot be larger than 1), so no refraction occurs in this case, and all the light is reflected back into the initial medium (total internal reflection). The value of the angle of incidence above which this phenomen occurs is called critical angle, and it is given by

Answer:
the answer is b mark me as the brqinlist
<span>d. The parallaxes beyond a few thousand light years are
too small to be measured with common instruments.
I'm not sure that parallax can even be used out to a few
thousand light years.
The NEAREST star to Earth has the BIGGEST parallax.
The star is Alpha Centauri. It's only 4 light years away
from us, and its parallax is 0.000206 of a degree !
I have no idea how astronomers can measure angles
so small ... and that's the BIGGEST parallax angle of
ANY star.</span>
Answer:Colloids include gels and emulsions; the particles do not settle, and cannot be separated out by ordinary filtering or centrifugtion
Explanation:they are homogenous/non crystalline