Question

A firecracker shoots up from a hill 145 feet high, with an initial speed of 80 feet per second. Using the formula H(t) = -16t2 + vt + s, approximately how long will it take the firecracker to hit the ground?
13 seconds
11 seconds
Nine seconds
Six seconds

Answer 1

Do you have any idea @cwrw238

Answer 2

I am thinking six

Answer 3

you need to solve
0 = -16t^ + 80t + 145

Answer 4

* -16t^2

Answer 5

Okay give me second and I will tell you what I get.

Answer 6

ignore the negative result

Answer 7

It is okay

Answer 8

i got 6.4
so thats 6

Answer 9

seconds

Answer 10

i gotta go for a while..