First, start constructing a "Whoa Belly". When you have the choice of how many levels you want your ride, select only one pyramid top piece. Now, go to the ride screen and click the options icon (the one with the gears moving together). On the option screen, there is an option on how much of a boost you want on your ride. Go up to 90 mph. Now, test your creation with guests on it, and watch the guests fly into the sky with the ride car, and laugh as the ride explodes when the people land.

Note: If you want to do this again, then demolish the old build building and create another using the same steps.