A boy walks from point C to point D which is 50 m apart. Then, he walks back to point C. what is his displacement of his whole journey ? A.25 m
B.75 m
C.50 m
D.0 m

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?

The air that we breath is made mostly of which gaseous molecule

(a) calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 10.0 g. silver has 47 electrons per atom, and its molar mass is 107.87 g/mol. (b) imagine adding electrons to the pin until the negative charge has the very large value 1.00 mc. how many electrons are added for every 109 electrons already present