A firecracker shoots up from a hill 150 feet high with an initial speed of 95 feet per second. Using the formula H(t) = −16t2 + vt + s, determine how long it will take the firecracker to hit the ground.

Question

anonymous · Answer

whats the answers is it multiple choice?

mertsj · Answer

That would be when its height is 0 and its initial height is 150 and its initial velocity is 95.  Plug in those values and solve for t.

anonymous · Answer

6.5 seconds
7.9 seconds
7.2 seconds
7.6 seconds
choices

mertsj · Answer

$$0=-16t^2+95t+150$$

anonymous · Answer

I got 7.2 seconds

anonymous · Answer

@Mertsj

mertsj · Answer

I'll check it out.

mertsj · Answer

$$x=\frac{-95\pm \sqrt{95^2-4(-16)(150)}}{-32}=7.23$$

mertsj · Answer

Sorry it took so long.  Had to tend to some domestic things.

anonymous · Answer

well i was right atleast lol its ok