일반물리학 2 — Interference: Problem 31

31 In Fig. 35-25, a broad beam of light of wavelength 683 nm is sent directly downward through the top plate of a pair of glass plates. The plates are 240 mm long, touch at the left end, and are separated by 51.4 \(\mu\)m at the right end. The air between the plates acts as a thin film. How many bright fringes will be seen by an observer looking down through the top plate?