a narrow beam of parallel sun rays is allowed to strike perpendicular to a grating constant of 2.00 micrometers. after passing the grid, they hit a screen, which is set up parallel to the grid with the grid plane, 40 cm behind the grid. Enter the length L of the 2nd order spectrum on the screen, counting from violet light of wavelength 400 nanometers to red light of wavelength 700 nanometers. The figure shows two pulses moving at a speed of 1.0 cm/s in a wire. The distance between two dots in the grid pattern is 1.0 cm.