1. The problem statement, all variables and given/known data A ball is thrown 2.8m/s vertically upward from a window that is 3.6m above the ground. calculate the amount of time the ball spends in the air. 2. Relevant equations quadratic equation d = Vi(t) + 1/2(a)(t)2 3. The attempt at a solution d = Vi(t) + 1/2(a)(t)2 3.6m =2.8 m/s[up](t) + 1/2(-9.8m/s2[up])(t)^2 0 = -4.9m/s2[up](t)2 + 2.8m/s[up](t) - 3.6m __________________ into the quadratic formula: t = [-(2.8) +- sqrt(2.82 - 4(-4.9)(-3.6))] / 2(-4.9) i end up with a negative under the root sign?