Question

An object is projected upward at a rate of 160 feet per second. Find the time when it is 384 feet above the ground..
The equation given is h=-16t^2+V(o)t.
384=-16*t^2+160*t

Answer 1

Good. Now put it all one one side of the equation, and use the quadratic formula. You should get t=4 and 6

Answer 2

-16*t^2+160*t-384=0?

Answer 3

Yep. Now, you can divide by -16 to get t^2-10t+24=0.
This factors into (t-6)(t-4)=0, so you get t=6 and 4

Answer 4

Thanks!