Projectile Motion Demonstration

Abstract

For a recent lecture, I went to our apparatus stock room and took out our venerable Sargent-Welch projectile apparatus1 that demonstrates that a dropped ball and a horizontally launched ball hit the floor at the same time, if they are simultaneously released. A problem with this apparatus is that its small size makes it difficult for a large class to see what is going on. Furthermore, the projectiles are ball bearings, which tend to roll under chairs, benches, etc.