Light that enters the new medium <em>perpendicular to the surface</em> keeps sailing straight through the new medium unrefracted (in the same direction).
Perpendicular to the surface is the "normal" to the surface. So the angle of incidence (angle between the laser and the normal) is zero, and the law of refraction (just like the law of reflection) predicts an angle of zero between the normal and the refracted (or the reflected) beam.
Moral of the story: If you want your laser to keep going in the same direction after it enters the water, or to bounce back in the same direction it came from when it hits the mirror, then shoot it <em>straight on</em> to the surface, perpendicular to it.
Answer:
D
Explanation:
The greater the mass, the greater the inertia, and vice versa.
Remark: This means that a more massive object has a greater tendency to resist a change in its state of rest or motion.
Newton observed the action of a prism on the white light and on red light. Because he did not control the event, this investigation of light was an observational study.
Hope this helps! (:
