Because 2,000 ping pong balls and 30 middle-school teachers floating in “zero gravity” isn’t something you see everyday, the kids should watch (or rewatch!) this 2010 ScienceBob video. From northropgrumman.com:
Zero gravity flights are performed using a specially modified aircraft, an FAA approved aircraft called G-Force One. The maneuvers are conducted in dedicated airspace 100 miles long by 10 miles wide. Specially trained pilots fly the aircraft in a series of maneuvers called parabolas, or arcs, between the altitudes of 24,000 and 32,000 feet.
At the beginning of each parabola, the aircraft climbs at a 45-degree angle. At the “top” of the parabola, the aircraft is “pushed over” into a controlled descent that creates a temporary zero-gravity environment. The teacher flights include approximately 15 parabolas ranging from low-gravity environments typical of the moon (1/6th G) or Mars (1/3 G) to complete weightlessness. At the end of each “weightless” period, which lasts approximately 30 seconds, the aircraft is gradually pulled out of the descent, reestablishing a more normal gravity environment inside the plane.