A rock is thrown upward from the height of 5 ft with an initial velocity of 50 ft per second. The height h(in feet) of the rock at time t seconds is h(t)=-16t^2+50t+5. When will the ball reach a height of 8 ft?
YOU THROW A ROCK, BUT ASK WHEN THE BALL REACHES 8 FT? oops!
8 = -16t^2 + 50t+5
0 = -16t^2 + 50t -3 Quadratic formula shows t =0.0611985 OR 3.0638 SECONDS
(One is for thr rock-ball on the way up...the other on the way down)