Introduction: Disc Shooter Physics Challenge

About: I'm a physics and chemistry teacher at a public school in Maryland and active in my local science teacher's association. I love building things and am teaching myself how to use arduino in electronics projects…
One challenge I present my honors physics students is to find the elastic constant of the arm of this small disc shooter. Along the way students discover that the shooter projects its ammo tangent to the circular path it was following when stuck on the arm of the shooter. To fire the shooter you slide the disc onto the shooter, pull back the lever, and release.

Materials provided to students:

disc shooter
discs
meter stick
electronic balance

Students are to determine a method of determining the elastic constant. One method of solving the problem is to use a combination of projectile motion and conservation of energy. The conservation of energy is elastic potential energy before firing is equal to kinetic energy immediately after firing. The speed in that formula can be determined if students fire the shooter horizontally from a measured height and measure the distance the disc travels.

I found these shooters several years ago from Oriental Trading Company, but you can also another type of toy shooter. I particularly like this model because of the additional tie in to circular motion but any other style will work.