Quadratic Function Word problem

Question

A t a Canada day celebration a firework is projected vertically in the air and reaches a maximum height of 120 metres. The path of the firework is parabolic and it lands 30 metres from the launch site Write a quadratic function that models the height of the firework as a function of the horizontal distance travelled.

1 The vertex in (p,q) form with no spaces is ____

2. a = ___ (as a fraction in lowest terms)

3. The height of the firework when it is 20 metres from the launch site is ___ (to one decimal place)

Answer 1

OK. This problem has some missing info, and I reckon you won't be able to count on any answer I could give you.

 

First, if the firework is launched vertically, then unless at launch it has a horizontal velocity already, it's going straight up and then back down. That would make your downrange distance 0. So there's that. No parabolic path for a trajectory that starts straight up, unless there is wind or something present.

 

Secondly, without a definition for a and (p, q), I'm not sure there's a reliable answer for that either.

I recommend going back to the source of this problem and checking to see if you were given all the starting info there is. Feel free to check back with me if you like!

Cheers!