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.

7.2 seconds

7.5 seconds

7.8 seconds

8.1 seconds

Question

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.

7.2 seconds

7.5 seconds

7.8 seconds

8.1 seconds

anonymous · Answer

solve the equatuion -16t^2 + 110t + 165 = 0

you should get -2.7 and 8.1 secs

answer is 8.1