# Thread: quadratics, text question

1. ## quadratics, text question

I don't really know where to start, how could i go about awnsering this question? any help at all would be much appreicated..

"The height h(t) in feet of an object t seconds after it is propelled straight up from the ground with an initial velocity of 60 feet per second is modeled by the equation h(t)= -16t^2 +60t At what times will the object be at a height of 56 feet?"

2. Originally Posted by 14041471
I don't really know where to start, how could i go about awnsering this question? any help at all would be much appreicated..

"The height h(t) in feet of an object t seconds after it is propelled straight up from the ground with an initial velocity of 60 feet per second is modeled by the equation h(t)= -16t^2 +60t At what times will the object be at a height of 56 feet?"

$-16t^2 + 60t - 56 = 0$

Solving for $t$ we find the following:

$t = 1.75$ or $t = 2$

It is logical that it will reach that height at 2 distinct times.

At 1.75 secs it is still going upward, and at 2 seconds it has already reached the vertex and is now moving downward.