Two extremely flat glass plates, 10.0 cm wide, touch at one end ...

[lbcchick]

Two extremely flat glass plates, 10.0 cm wide, touch at one end but are separated by a thin wire at the other end, forming a wedge.
 
  Light with a wavelength of 450 nm shines almost perpendicularly on the glass and forms fringes which are 1.80 mm apart. What is the diameter of the wire?
  A) 25.0 m B) 10.0 m C) 20.0 m D) 12.5 m E) 17.5 m

Question 2

A 35-mm digital camera using a standard 50.0 mm lens is focused on a 1.80 m tall person who is standing 3.25 m from the lens. You now refocus the camera on a 15.0 cm tall flower that is 75.0 cm from the lens.
 
  (a) In refocusing, by how much did you move the lens? Did you move it toward the film or away from it?
  (b) What is the height of the flower's image on the CCD sensor?

[chereeb]

Answer to Question 1

D

Answer to Question 2

(a) 2.79 mm, away from the film (b) 10.7 mm

[lbcchick]

Wow, this really help

[nanny]

Excellent