3. A research student uses a laser beam incident normally on a grating having 400 lines/millimeter. The student observes that the distance of the first point from the center point (the

center maximum intensity) is 10 centimeters if the distance between the grating to the screen is 1.5 meter. The student then utilizes this laser by shining at the normal incident to a small slit. It produces a diffraction pattern as shown. The distance between the first minimumintensities is 24.0 centimeters. If the distance between the grating to the screen is 1.5 meter, what is the width of the slit in micrometer? Incident