Question

A projectile is launched upward from a height of 704 feet with an initial velocity of 112 ft/s. The equation gives the height h after t seconds. find the number of seconds until it returns to the ground

Answer 1

We are given the data ho equal to 704 feet and vo equal to 112 feet per second. We apply then kinematics equation: h = ho + vot - 1/2 gt2. Substituting to the given equation, 
h = 704 + 112t - 1/2 * 32*t2when h is equal to zero,0 = 704 + 112t - 1/2 * 32*t2t is equal to 11 seconds