Question

If a stone is tossed from the top of a 230 meter building, the height of the stone as a function of time is given by h(t) = -9.8t2 – 10t + 230, where t is in seconds, and height is in meters. After how many seconds will the stone hit the ground? Round to the nearest hundredth’s place; include units in your answer

Answer 1

h(t) = 9.8t^2 - 10t +230 = 230,
9.8t^2 - 10t = 0,
Factor out 2t:
2t(4.9t - 5) = o,
2t = o,
t = 0,

4.9t - 5 = 0,
4.9t = 5,
t = 5 / 4.9 = 1.02 s = time to hit gnd.