how far must he mirror mz of the michelson interferometer be moved so that 1600 fringes of laser light move across a line int he field of view

The question is not complete. Let me explain Michelson interferometer and how to calculate a question like this.

Answer 4.85 * m

Explanation:

The Michelson Interferometer is an instrument which produces interference fringes by splitting a light beam into two parts, it then recombines them after they have travelled different optical paths.

The formula to measure the minute displacement is Δd=m * λ/2

where m is the number of fringes passing a given point as the movable plane mirror is moved

and λ is the monochromatic lamp of wavelength

In the question, m = 1600. Let us assume that the wavelength is 606 nm

Solution

Δd=m * λ/2

Δd=1600 * 606nm/2 = 1600 * 303nm = 484800nm

We convert the nm to m (nm / )

4.85 * m

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.