A rocket is launched from atop a 105ft cliff with initial velocity of 156 ft/s Height above ground a time t is given -16t^2 + 156t + 105 = h. When will it hit the ground after launch?

Question

A rocket is launched from atop a 105ft cliff with initial velocity of 156 ft/s  Height above ground a time t is given -16t^2 + 156t + 105 = h.  When will it hit the ground after launch?

Steve · Answer

clearly, when -16t^2 + 156t + 105 = 0