A sheet of glass having an index of refraction of 1.52 is to be coated with a film of material having a refractiveindex of 1.75 such that green light with a wavelength of 525 nm (measured in vacuum) is preferentially transmitted when white light is incident normally on the film. What is the minimum thickness of the film that will achieve this result

Electric field of the earth. the earth has a net electric charge that causes a field at points near its surface equal to 150 n> c and directed in toward the center of the earth. (a) what magnitude and sign of charge would a 60-kg human have to acquire to overcome his or her weight by the force exerted by the earth’s electric field? (b) what would be the force of repulsion between two people each with the charge calculated in part (a) and separated by a distance of 100 m? is use of the earth’s electric field a feasible means of flight? why or why not?