One of the mirrors of a Michelson interferometer is moved, and a shift of 140 fringes in the output pattern occurs. If the device is illuminated with 500 nm light, how far was the mirror moved

0.035mm

Explanation:

Given; wavelength λ = 500nm = 0.0005mm, Number of fringe m = 140, d = ?

In Michelson interferometer, distance moved by the mirror is given by,

d = m*λ/2

d = 140*0.0005/2 = 0.035mm

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s