Blog 7: More Passing Physics

This past week I had practice almost everyday, so I had a lot of time to reflect about the physics of volleyball. Since we were learning about moment of inertia, I started to apply it to some of my volleyball technique. We learned that objects with the same mass have a greater moment of inertia if they have a large radius, or their mass is more spread apart. When I dive to get a ball, in order to stand up quicker, I either roll to the side and stand up or roll back over my shoulder. These maneuvers require quick rotation to stand up faster. I realized that the more I compact my body when I roll, the faster I can stand up and be ready for the next ball. My rotation would be faster because the radius used to calculate moment of inertia would be smaller, than if if my arms and legs were straight out. This is a picture of me right before I go into a roll.


In dance, we do a similar roll to the roll over the shoulder I do in volleyball, but for the dance row, the goal is to keep your legs as straight as possible. Since this increases the radius for the moment of inertia, this roll requires more torque and is not as fast as the volleyball roll.