Hello, I am having trouble with this physics problem and I really need a help.

Which of the following is a source of heat for magma formation? magma plumes in the continental crust friction due to divergence friction due to subduction magma plumes in the oceanic crust

The most important difference between a wedge and an inclined plane is a. their size b. their shape c. how they are used d. what they are made of

Suppose you have three polarizing filters, with the second at an angle of 42∘ to the first and the third at an angle of 90∘ to the first. by what perfect will the original intensity of unpolarized light be reduced to after passing through all three filters?