Question

a flashlight is turned on and shines a beam of white light onto a blue plastic film, as shown. how will the beam of light from the flashlight appear on the white screen, and why? the film will absorb all the colors except blue, and blue light will appear on the white screen. the film will absorb all the light waves, and no light will appear on the white screen. the film will transmit all the light, and a white light will appear on the white screen. the film will diffuse all the light, and a faint white light will appear on the white screen.

Explanation:

When white light (composed of all visible colors) hits a blue object (like the plastic film), the object absorbs all wavelengths of light except blue. The blue wavelengths are transmitted (or reflected, in some cases; here, as it's a film letting light through to the screen, it's transmission of blue). So the blue light passes through the film to the white screen, which then shows blue. The other options are incorrect: the film doesn't absorb all light (so no light on screen is wrong), doesn't transmit all light (so white light on screen is wrong), and diffusion isn't the key process here (diffusion scatters light, but the color filtering is about absorption/transmission of specific wavelengths).

Answer:

The film will absorb all the colors except blue, and blue light will appear on the white screen.