Trajectory with drag

I mentioned today in class that Halliday, Resnick, & Walker's diagram of a projectile trajectory under the influence of air drag was mistaken. I've created an Excel spreadsheet (just click on "File" and then "Download" to view on your computer) that illustrates what I meant. As you can see from the graph in the Excel spreadsheet, also shown here...

...a major difference that drag imparts is that the trajectory is not symmetric across the maximum!

Try changing the input values in Row 2 of the spreadsheet. How does a change in each input value impact the shape of the trajectory?

If you're really feeling adventurous, take a look at the formulas that are set up to calculate the motion! How does it work?