a rock is throw upward with a velocity of 24 meters per second from the top of a 38 meter cliff, and it misses the cliff on the way back down. When will the rock be 2 meters from ground level?

Answer 1

the equation is
h = -4.9t^2 + 24t + 38 , where h is the height above ground level, and t is seconds
so you want
2 = -4.9t^2 + 24t + 38
4.9t^2 - 24t - 36 = 0
use the quadratic formula to find t, reject the negative value.