The height of a tower is 25m. A stone is thrown upwards from the top of the tower at 20.5m/s. Calculate the total time the stone was in the air.
hf=hi+vi*t-1/2 g t^2
0=25+20.5t-4.9 t^2
use the quadratic equation to solve for time t.
0=25+20.5t-4.9 t^2
use the quadratic equation to solve for time t.