How much wood could a woodchuck chuck if a woodchuck could chuck wood?

What are the north and south poles of a solenoid change with?

What is a subatomic particle with a negative charge and very little mass?

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?