If a ball is thrown downwards with an initial speed of 5m/s off a tall building and air resistance is neglected, How fast will it be moving in 3 seconds and how far will it travel. Show all of your
calculations.

What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 480 ? the index of refraction of the film is 1.34, and there is air on both sides of the film. express your answer in nanometers. hint 1. how to approach th