APSU’s pingpong cannon blasts through Governor’s School
High school students attending the APSU Governor’s School for Computational Physics this summer learned pingpong balls can pierce a piece of ¼-inch-thick plywood.
But only with the help of a specially built pingpong cannon.
Bryan Gaither, laboratory manager at Austin Peay’s Department of Physics, Engineering and Astronomy, built the cannon earlier this year using a clear 8-foot PVC pipe. The pipe is 1 ¼-inches wide, just wide enough to allow pingpong balls through.
At the June 11 Governor’s School demonstration, he capped the ends of the pipe with Mylar aluminum then sucked the air from the tube, creating a vacuum. Then he punctured the seal.
Dr. B. Alex King III described what happened next to the Governor’s students this way: “The air rushes back in on this end, grabs the pingpong ball and throws it to the other end. The pingpong ball is going fast enough at the end to go through the can.”
The air rushes in at such a force, it pushes the ball to speeds of more than 450 mph, Gaither said.
He fired the cannon three times, twice at aluminum cans and once at the plywood. The ball pierced its target each time, leaving an oddly perfect round hole in the plywood after the last shot.
After the ball exits the cannon and blasts through its target, it slows immediately because of air drag, traveling only a couple of feet from the end of the pipe.
To learn more about Governor’s School for Computational Physics at Austin Peay, go to www.apsu.edu/governors-school/.