Question
Assume you are throwing a baseball up from the top of a building. The equation for the height of the ball, h, at time, t, is represented by the equation: h=-16t^2+64t+512
(5 points) After how many seconds does the ball reach 560 feet? Explain what your answer means.
(5 points) After how many seconds does the ball reach 560 feet? Explain what your answer means.
Answers
Reiny
h=-16t^2+64t+512
we want h = 560
560 = -16t^2+64t+512
16t^2 - 64t + 48 = 0
t^2 - 4t + 3 = 0
(t-1)(t-3) = 0
it happened after 1 second AND after 3 seconds, once on its way up and then again on its way down
we want h = 560
560 = -16t^2+64t+512
16t^2 - 64t + 48 = 0
t^2 - 4t + 3 = 0
(t-1)(t-3) = 0
it happened after 1 second AND after 3 seconds, once on its way up and then again on its way down