If a star 100 light years from Earth is beginning to expand into a giant star, how long will it take for astronomers to observe this development? Explain.

What is magnetic flux? explain faraday's law of induction.

What is the angular momentum of the bar about the axle?

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?