<PRE><B>Question 395136</B>
A foul ball leaves a bat, hits home plate, and travels straight up with an initial volocity of the rebound of 64 ft/s. How many seconds later will the ball be 64 ft above the ground.I figured it out till I factored out the 16 and then got lost.
H=64t-16t^2
64=64t-16t^2 has 64 subtracted from both sides and becomes the following:
0=-16t^2+64t-64
---
Comment: You ignored the negative on the 16.
------
0 = -16(t^2-4t+4)
---
t^2-4t+4 = 0
(t-2) = 0
t = 2
============
Cheers,
Stan H.
</PRE>