A firecracker shoots up from a hill 165 feet high with an initial speed of 110 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

From the way it was written:
v = magnitude of 110 ft/s
s = height = +165

H(t) = 0 when it's "on the ground"

Can you solve it now?

anonymous · Answer

165 ft that is.

anonymous · Answer

There was no angle indicated so we have to assume v is v$_y$, the vertical component and H(t) is a formula for the vertical displacement with respect for time.  Realistically you want an angle.

And if you want to assume it land back as where it shot from, then you'd solve for H(t) = 165 ft instead of zero.