Complete Question
You are performing a double slit experiment very similar to the one from DL by shining a laser on two nattow slits spaced
meters apart. However, by placing a piece of crystal in one of the slits, you are able to make it so that the rays of light that travel through the two slits are Ï out of phase with each other (that is to say, Ao,- ). If you observe that on a screen placed 4 meters from the two slits that the distance between the bright spot closest to center of the pattern is 1.5 cm, what is the wavelength of the laser?
Answer:
The wavelength is 
Explanation:
From the question we are told that
The distance of slit separation is
The distance of the screen is 
The distance between the bright spot closest to the center of the interference is 
Generally the width of the central maximum fringe produced is mathematically represented as

=> 
=> 
=> 
Using the constant acceleration formula v^2 = u^2 + 2as, we can figure out that it would take a distance of 193.21m to reach 27.8m/s
(a) 1200 rad/s
The angular acceleration of the rotor is given by:

where we have
is the angular acceleration (negative since the rotor is slowing down)
is the final angular speed
is the initial angular speed
t = 10.0 s is the time interval
Solving for
, we find the final angular speed after 10.0 s:

(b) 25 s
We can calculate the time needed for the rotor to come to rest, by using again the same formula:

If we re-arrange it for t, we get:

where here we have
is the initial angular speed
is the final angular speed
is the angular acceleration
Solving the equation,

It’s a total of 16 cm because it starts at 0 moves then moves to left then the right then the left