The Physics of Broken Ornaments

The day after Thanksgiving my family usually decorates for Christmas. As anyone who has decorated a tree knows, ornaments drop, and sometimes they break. As we were decorating this year, I dropped a snowman ornament that luckily did not break. The safety of this ornament is due to physics.

To start, we know that energy is conserved, so 1/2mv2=mgh. Mass will cancel, and we can find the final velocity given the height from which the ornament fell. From there, the impact force can be found given W=KE or Fd=1/2mv2. The distance in this equation is that which is traveled after impact. In my case, this was a hardwood floor, which is very impermeable and would have a value that is very close to zero. The force, therefore, would depend on the ornament's mass, the height of the fall, and the surface onto which it falls. The impact force, however, did not exceed the force required to break ceramic and resulted in an unharmed snowman.

In order to protect ornaments this holiday season, physics would suggest a couple of things. First, having more fragile ornaments closer to the ground would reduce the potential energy and eventually reduce the overall force of the fall. Second, having the tree on some sort of mat or carpet would increase the distance the ornament would travel after the fall and further reduce the impact force. Finally, some materials, like wood or ceramic, have a higher resistance to force than other materials, such as glass. The materials that can withstand more force will be less likely to break no matter the location on the tree. Knowing this can reduce broken ornaments this holiday season.