9. A student and her lab partner create a single slit by carefully aligning two razon blades to a separation of 0.500 mm. When a helium-neon laser at 633 nm illuminates the slit, a diffraction pattern is observed on a screen 1.25 m beyond the slit. Calculate (a) the angle dark to the first minimum in the diffraction pattern and (b) the width of the central maximum. 10. Monochromatic light at 625 nm illuminates a diffraction grating with 325 lines/mm. Determine (a) the angle to the first-order maximum, (b) the highest order that can be observed with this grating at the given wavelength, and (c) the angle to this highest-order maximum. 11. Microwaves of wavelength 5.00 cm enter a long, narrow window in a building that is otherwise essentially opaque to the incoming waves. If the window is 36.0 cm wide, what is the distance from the central maximum to the first-order minimum along a wall 6.50 m from the window?