Here's that other question. (I'm not trying to get anyone to do the work for me, it's just that the 3 questions are due tomorrow and I'm like this ...)
A warning flare is fired vertically from the top of a tower. It's height h in metres after t is given by the equation h = 10 + 40t - 5t²
A) how high is the tower
*For this I substituted t for 0(zero) and got an answer of 10m.
B) what height is reached by the flare.
*For this I "completed the square" and got "h=-5(t-4)² + 78"...don't know if that's right of what to do after*
C) how long is it in the air (until it hits the ground)
I have no idea here