Width of a Hair Lab
The goal of this lab was to measure the width of a single strand of my hair by using laser diffraction and interference patterns.
Experimental Process
Set-up
A laser is shined through a thin piece of hair and a split pattern is formed on the wall.
Measurements
To measure the width of a hair, the equation mλ= ds/D must be used.
- Where m is the number of constructive interferences
- λ is the wavelength of the laser
- d is the width between slits (hair width)
- s is the distance between interference patterns
- D is the distance from the hair to the wall
Using the measurements we collected:
m = 2
λ = 532nm = 0.0000532cm
d = what we are solving for
s = 1cm
D = 190cm
Step 1: multiply both sides by D (mλD= ds)
Step 2: divide by s (d = mλD/s)
Step 3: plug in measurements
d = (2)(0.0000532)(190)/(1) = 0.02012cm
The width of my hair is 0.02 cm thick