Asked by Anonymous

A rock is dropped from a high bridge. At the end of 3sec of free fall. The speed of rock is, in centimeters per second
Answered by Damon
if a = -g
then
v = Vi - g t
h = Hi + Vi t - (1/2) g t^2
so
v = 0 - 9.81 * 3
so speed which is |v| is about 30 m/s