For this case we have an equation of the form: h (t) = (1/2) * (a) * (t ^ 2) + vo * t + h0 Where, a: acceleration vo: initial speed h0: initial height By the time the ball hits the ground we have: h (t) = 0 Substituting values: 0 = - (1/2) * (9.8) * (2 ^ 2) - 25 * 2 + h0 h0 = (1/2) * (9.8) * (2 ^ 2) + 25 * 2 h0 = 69.6 m Answer: the building is 69.6 m high
