The refractive index of a material is a dimensionless number that describes how fast light travels through the material. It is defined as n={\frac {c}{v}}, where c is the speed of light in vacuum and v is the phase velocity of light in the medium.
the ratio of the velocity of light in a vacuum to its velocity in a specified medium.
An example of a molecule:
b) Protein
I am pretty sure it is A Becoming warm
Since it’s moving and causing friction which makes it warm
Hope this helps
Mark me brainliest
Depends on how well built he is probably for the average American 8 MPH
