Afirecracker shoots up from a hill 140 feet high, with an initial speed of 100 feet per second. using the formula h(t) = −16t^2 + vt + s, approximately how long will it take the firecracker to hit the ground?

five seconds
seven seconds
nine seconds
11 seconds

The right answer for the question that is being asked and shown above is that: "Seven seconds." A firecracker shoots up from a hill 140 feet high, with an initial speed of 100 feet per second. Using the formula H(t) = −16t^2 + vt + s, approximately it will take Seven seconds for the firecracker to hit the ground.

X=y+4 is the answe