A mine car (mass=500 kg) rolls at a speed of 0.50 m/s on a horizontal track, as the drawing shows. A 160-kg chunk of coal has a speed of 0.87 m/s when it leaves the chute. Determine the speed of the car–coal system after the coal has come to rest in the car.

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