You can add the path of the projectile by creating a data set that calculates the x and y positions for each time, and plotting it as a second series on the graph. You will need to change the order of the series so that the moving projectile is drawn after the projectile. You can add the second series, rename both series, and change their order using the “Select Data…” option when you right click on the graph. See the image below as needed.
With a bit of cleverness, you can adapt this technique to other physical systems. If you have the Office Mix add-in installed in PowerPoint, you can capture a movie of the graph in action, and then use it elsewhere as you like.