What is the focal length of a pair of contact lenses that will ...

[yoooooman]

What is the focal length of a pair of contact lenses that will allow a person with a near point of 125.0 cm to read a newspaper held 25.0 cm from his eyes?
 
  A) -100 cm
  B) -31.3 cm
  C) 10.2 cm
  D) 20.8 cm
  E) 31.3 cm

Question 2

Triton, the largest of Neptune's moons has a retrograde rotation. This means that it revolves about Neptune in the opposite direction to Neptune's direction of rotation about its own axis.
 
  The gravitational attraction of Triton causes tides on Neptune, which gradually slow down its rotation about its own axis. What consequences does this have for Triton?

[chevyboi1976]

Answer to Question 1

E

Answer to Question 2

Since the angular momentum of the Neptune-Triton system has to be conserved, a decrease in the angular momentum of Neptune about its axis must be balanced by an increase of Triton's angular momentum about that axis. But since Triton is orbiting Neptune in the opposite direction, its angular momentum will actually decrease. Triton's orbit will thus gradually decay until it either breaks up or falls into Neptune.

[yoooooman]

Thank you!

[chevyboi1976]

Always glad to help...