7) In an interference experiment, red light (660 nm) passes through a double slit. On a screen 1.5 m away, thedistance between the 1st and 12th dark bands is 13.1 cm. What is the separation of the slits in m?

8) Light of wavelength 570 nm passes through a 32 m single slit and produces a 6.7 cm wide central maximum. How far away is the screen that displays the diffraction pattern from the slit?

9) The angle to a bright fringe in a single-slit interference experiment is 3.5. What order must this maximum be, if the wavelength of light is 580 nm and the width of the slit is 52 m?

10) Waves need a medium to travel through. Describe how it is possible f