if and object thrown upward dropped or thrown downward and travels straight line subject onl

If and object is thrown upward, dropped, or thrown downward and travels in a straight line subject only to gravity, the height h of the object above the ground (in feet) after t seconds is given by h=-16t^2+vt+h, where h is the height of the object when t=0 and v is the velocity of the object at time t=0. Note that the value of v is taken to be positive if the object moves upward and negative if it moves downward. A ball is thrown upward from ground level wit an initial velocity of 64 ft per second. In how may seconds will the ball reach the given height? a) 64ft b)60ft