An elephant pushes 2000 N on a load of trees. It pushes the trees 150 m. How much work did the elephant do? Be sure to show your work.

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