f an object is propelled upward from a height of s feet at an initial velocity of v feet per second, then its height h after t seconds is given by the equation h= 16t^2+vt+s, where h is in feet. If the object is propelled from a height of 12 feet with an initial velocity of 96 feet per second, its height h is given by the equation h=16t^2+96t+12.

After how many seconds is the height 120 feet?