Posted by shawni on .
while standing at the edge of the roof of a building, you throw a stone upward with an initial speed of 7.79 m/s. the stone then falls to the ground 14.3 m below. At what speed does the stone impact the ground? how much time is it in the air? g=9.81 m/s^2 and ignore air resistance

physics 
drwls,
V^2/2 increases by g*H m2/s^2, the potential energy loss.
The time in the air is the sum of the times spent going up and down.
The time going up is t1 = 7.79 m/s/g
The time spent coming down is given by
Vyo*t2 (g/2)*t2^2 = 14.3 meters
Solve for t2