If an object is given an initial velocity straight upward of v0 feet per second from a height of s0 feet , then its altitude's after 1 second is given by the formula
S= -16t2+ v0t + s0
An arrow is shot straight upward with a velocity of 96 feet per second (ft/sec) from an altitude of 6 feet. For how many seconds is this arrow more than 86 feet high.