(b) A uniform beam AB, 10m long and of mass 40kg, rests on two supports, one at A and the
other 2m from B. If a weight of mass 20kg is
attached to the beam at a point om from A, find
the reactions from the supports.​

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