posted by kennedy .
1) Thin films, such as soap bubbles or gasoline on water, often have a multi-coloured appearance that sometimes changes while you are watching. Explain the multi-coloured appearance of these films and why their appearance changes with time.
2) Yellow light is incident on a single-slit 0.0315 mm wide. On a screen 70.0 cm away, a dark band appears 13.0 mm from the centre of the bright central band. Calculate the wavelength of the light.
1. is the film the same thickness throughout? (ans NO) What is interference?
2. This is a standard formula.