physics 2 lab
DESCRIPTION
Developing a model of electric charge to discover nature of charge.TRANSCRIPT
Valeria Vasconcellos Lab 11 April 25, 2013 Procedure: A laser was shone through three objects: a diffraction grating glass, a rabbit muscle, and the lens of a butterfly’s eye. The lines that were emitted onto the board behind the object were recorded and the diffraction pattern was analyzed. Part I: Diffraction Grating Q1: Simplification of the following equation: d sin θ = n λ
Where L is the distance from the object to the backdrop, and lambda, the wavelength emitted by the laser, is equal to 6.328-‐5cm. With L = 9.7cm
n Xn (cm) d (slits/mm) -‐1 2.3 -‐ 364.5959745 1 2.3 364.5959745 -‐2 4.6 -‐338.5640947 2 4.3 320.2147754 -‐3 7.6 -‐324.8766281 3 7.1 311.1262826
Average: 4.7 337.328955 Std. Dev.: 2.274203157 22.90433107
Q2: The average value for d as seen in the table above is 337.328955 slits/mm. The gradient written on the glass is 300 slits/mm. The percent error is 12.443%. Part II: Rabbit Muscle Following the same method, we were able to measure the spacing between the Z-‐bands of a sample of rabbit muscle. Where L = 9.3 cm
n Xn (cm) d
-‐1 2.7 -‐
440.5976531 1 2.3 379.3912748
-‐2 5.6 -‐
407.5930475 2 4.4 337.9175744
Average: 3.75 391.3748875 Std. Dev.: 1.532970972 43.54002242
Part III: Insect Eye Q1: Plotted diffraction pattern with corresponding measured lengths, x1, x2, x3.
Conclusion: During this lab, we took different objects and analyzed the ways each diffracted the light of the laser. Each object produced a different diffraction pattern. For the grating glass, the pattern was a line of dots; the rabbit muscle produced a central dot with arcs on either side; and the butterfly eye produced a hexagonal pattern. (It’s difficult to tell from our picture, but the pattern was a series of dots that created the corners of a hexagon.) From these patterns, we calculated the number of slits per millimeter using a simplified version of the equation d sin θ = n λ.