What colors of light are reflected by the color magenta?

In which of the following is positive work done by a person on a suitcase

Awave with a frequency of 500 hz is traveling at a speed of 100 m/s.what is the wavelength?

Light from two different sources are incident upon the same side of a polarizing filter. light from one source is polarized with total intensity ip, while light from the other source is unpolarized with total intensity iu. as you rotate the polarizing filter through 360 degrees, the intensity of the transmitted light on the other side varies by a factor of 9. what is the relative intensity of the initial polarized source to the unpolarized source, or ip/iu?