Answer:D.Refractive Indez
Explanation:
It is usually expressed the other way: the ratio of the speed of light in a vacuum to the speed of light in a medium. In that case, it is called the "index of refraction".
Everywhere particles dont stay in one place they move elsewhere
Answer:
8m/s
Explanation:
Average Speed = distance / time = 400/50 = 8m/s