ma = bsin(0m)We use diffraction in two ways in this lab, which superficially seem different, but are really the same. First, we "project" the diffraction pattern on a wall with a laser. In this setup, the pattern forms in the following way: Projection Wall Laser Diffraction d _ ' 9 m m2 (wavelength A) (W'dth b) m / m=l m=0 \\ m:- \\' m=-2 D Second, we see the diffraction pattern as a set of virtual images of the LED, seen through the diffraction grating. This is illustrated in the following diagram: LED Diffraction (wavelength A) . (Wldth b) Virtual image;\\ Eye of LED em Note that in the latter case, the "real" angles are the ones we see in the eye (since that's the diffraction of the actual laser beams), but it looks like the laser is "behind" the diffraction grating at exactly the same angle. Hence, we can treat the angle we see the (virtual) image at as a measurement of the angle of diffraction. art I Which color LED has diffracted images that are closer together? Blue Which diffraction grating has images that are closer together? 500lines/mm As you move the wall towards the laser, what happens to the distance between spots? Decreases