A ball is launched into the sky at 272 feet per second from the roof of a skyscraper 1,344 feet tall. The equation for the ball’s height h at time t seconds is h = -16t2 + 272t + 1344. When will the ball strike the ground?

Question

Luigi0210 · Answer

Using the quadratic formula, you actually get some nice roots. Have you tried using it?

Luigi0210 · Answer

http://prntscr.com/muq55r this is what your equation looks like

Luigi0210 · Answer

You could solve it graphically by looking for the zeros (where it lands on 0 for x).

Or do you want to solve it mathematically?

newlearner132 · Answer

mathmaticaly, i need to know when it will hit the ground

Luigi0210 · Answer

Okay, so we'll use the quadratic formula.

$\Large \frac{ -b \pm \sqrt{4ac}}{2b} $

With your equation: 
a= -16
b= 272
c= 1344

Try plugging them in.

Luigi0210 · Answer

Whhops, hold on

$\Large \frac{-b \pm \sqrt{b^2-4ac}}{2a} $

There ya go

Luigi0210 · Answer

The quadratic formula will find roots for x(if there are any).

In your case, x is the number of seconds. 
So you will only use one of those values that you calculate.

Luigi0210 · Answer

Since you can't have negative time, go with the positive value

newlearner132 · Answer

i got the rest from here, i understand the math, usualy, i just have problems applying it sometimes

Luigi0210 · Answer

alright, good luck

newlearner132 · Answer

do i wright it as x=(quad formula)

newlearner132 · Answer

nevermind