Quadratics in the Real World

Date: 07/30/98 at 09:19:53
From: Eric Makhni
Subject: Quadratics in the real world

Hi,

I am participating in a math contest, and I am making a speech about 
quadratics on the pre-calculus level. I am going to speak on 
"Quadratics: How Do They Help Us In the Outside World?" and I have 
been looking for information.

Thanks,
Eric M.

Date: 07/31/98 at 22:14:02
From: Doctor Jeremiah
Subject: Re: Quadratics in the real world

Hi Eric:

Quadratics are used in the real world. Even NASA uses quadratics when 
they hurl rockets into space.

One example of a quadratic is a parabola. It is a quadratic because 
the highest power term in the equation of a parabola has an exponent 
equal to 2.  An example of a quadratic that is a parabola is:

   x = c + b * x + a * x^2  <== notice the exponent

If we use different letters we get:

   y = D + V * t + A/2 * t^2

which is the equation for the distance that something will move 
vertically when rising against gravity.

So if you wanted to know how high a rocket would go (to determine if it 
would make it to outer space) you would use a quadratic like that one.

In the equation y = D + V * t + 1/2 * A * t^2:

   y is the vertical distance
   t is the length of time
   D is the starting distance (perhaps 0)
   V is the starting vertical velocity (perhaps 0)
   A is the acceleration

The acceleration A would be the rocket's acceleration minus the 
Earth's acceleration.

I hope that gives you a good example. If you need more information 
mail back and I will try to help.

- Doctor Jeremiah, The Math Forum
Check out our web site! http://mathforum.org/dr.math/