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:
If one side of the train is positive and the other is negative they will attract if they are the same then they will repel.
Explanation:
If both are positive they will repel if both are negative they will repel and if they are opposites they will attract.
I believe the answer is x
Answer: 
Explanation:
Given
Distance putty has to travel is 3.5 m
The initial speed of putty is 9.50 m/s
Using equation of motion to determine the velocity of putty just before it hits ceiling
So, the velocity of putty just before hitting is
You cant skip nothing. All the lessons are important! Sorry about you free time :/
