Anti-reflective coatings on lenses use thin-film interference to eliminate the reflection of a particular color. suppose a glass lens (ng = 1.53) is covered with a thin film (nf = 1.31) to prevent green light (λ = 534 nm) from being reflected.

(a) write an expression for the minimum thickness the film can have, t.
(b) calculate the minimum thickness, t, in nanometers?

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.

What is the relationship between ozone and smog?

The path of a satellite orbiting the earth causes it to pass directly over two tracking stations a and b, which are 51 miles apart. when the satellite is on one side of the two stations, the angles of elevation at a and b are measured to be 87 degrees and 84 degrees, respectively. (a) how far is the satellite from station a? (b) how high is the satellite above the ground?