Question

I'm currently studying for my physics final right now and I could use some help. Here's three questions for you that are unrelated to each other.

1) A diver in the water shins light up at an angle underneath a thick glass bottom boat. At what angle would none of the light be observed by someone standing in the boat?

2) The central peak of a pattern formed by a slit that is 42.5 um wide has a width of 2 degrees. What wavelength is the light passing through the slit? Is it visible light?

3) A typical pole for a pole vault is 4 meters in length. How fast would someone have to run with the pole for an observer at rest to measure the pole to be 3 meters in length?

A thorough explanation would be greatly appreciated.

Answer 1

1.

(critical angle)

3.