The x-acis of a trajectory represents its C
The refractive index for glycerine is

, while for air it is

.
When the light travels from a medium with greater refractive index to a medium with lower refractive index, there is a critical angle over which there is no refraction, but all the light is reflected. This critical angle is given by:

where n1 and n2 are the refractive indices of the two mediums. If we susbtitute the refractive index of glycerine and air in the formula, we find the critical angle for this case:
F = m*a, mass times acceleration.
F = 15*10 = 150 N
Answer: As Earth spins on its axis, we, as Earth-bound observers, spin past this background of distant stars. As Earth spins, the stars appear to move across our night sky from east to west, for the same reason that our Sun appears to “rise” in the east and “set” in the west.
Explanation:
All sources of energy on the planet (excluding nuclear reactions) are ultimately attributable to the sun. 'Fossil fuels' are derived from what once were living organisms, and all sources of food begin with primary producers (plants and algae which utilize photosynthesis).