Two point charges are separated by 6 cm. the attractive force between them is 20 n. find the force between them when they are separated by 12 cm. (why can you solve this problem without knowing the magnitudes of the charges? )

Several mountains together form a mountain . a few of these combined form a mountain system. several systems combined form a mountain , which can stretch thousands of miles in length.

Which is not a source of noise pollution? a)airplanes b)acid rain c)machines d)cars

(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