Question

A ball is thrown upward with an initial velocity of 96 ft/sec from a height h, in feet, after t seconds is given by (h)t=-16t^2+96t+640 after how long will the ball reach the ground?

Answer 1

we simple want to find the roots of this quadratic... this is because we call the ground h=0 so we just want to find what time t makes the h=0, aka the roots... once you have both roots, one will make more sense than the other

Answer 2

for example if you get t=9s or -4.5 secs then you know it is 9secs bc time cannot be negetive

Answer 3

those are not the roots, i was just giving an example....

Answer 4

use the quadratic equation maybe!

Answer 5

or use kinematics....