Real Life Parabolas.

  I can tell you the equation for a parabola since I teach it at least once a year but I have trouble applying it in real life because most of the textbooks I use only provide theoretical situations, not real situations.

We observe parabolas in real life when we watch a ball thrown because its natural trajectory is parabolic.  This doesn't matter if its in baseball or basketball.

You see the parabolic shape in reflectors, flashlights, and satellite dishes.  The reason the telescope was built in Arecibo, Puerto Rico is because there existed a hole which perfectly shaped for it. If you look at car headlights, you'll see they are backed by a wonderful parabolic shape which causes the lights to shine in its pattern. In addition, spot lights also use the parabolic shape to project light outwardly.

Even the curved parts of the suspension bridge have a parabolic shape as the cables are put under pressure.  In addition, if you look at water fountains, the water is thrust up and  when it reaches a certain height, it comes down in a parabolic shape. Of course, you use the parabolic shape when launching birds in any of the Angry Birds games, or when launching the pumpkins at the pumpkin chunking competition.

What about the McDonalds eating establishments with their double arch made out of two parabolas joined to create the M.  If you've ever looked at roller coasters, the whole ride is made up of multiple parabolic shapes hooked together to form a pathway for the cars.

Even skis have started having a parabolic shape carved into each side because these cuts make it easier to turn the skis due to a shortened turning area.  Then there is  the beautiful banana that is found in the shape of a parabola.   Just look at the world around you.  The slinky as it crawls down the steps forms a parabolic shape as it moves from step to step or the path of jumping fish or dophins as they rise out of the water before diving in.

I think its important to provide students with an opportunity to research these items and then figure out the actual equations to describe the specific shape. My college prep will be studying parabolas soon and I plan to have them research real life parabolas before beginning the mathematics behind them.

Let me know what you think.  I'd love to hear.