. A man throws a stone vertically downward with an initial speed of 12.0 m/s from the roof of a building, 30.0 m
above the ground. (a) How long does it take the stone to
reach the ground? (b) What is the speed of the stone at
impact?

Suppose you use a machine that gives you a mechanical advantage of 2 to achieve an output force of 30newtons what must the input force be

What is a possible result of higher air temperature caused by global warming

(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