Welcome to the Physics of Tumbling!
For our web assign project we decided to study the physics of tumbling, something that looks so hard and has everything to do with physics! This web page will describe step by step the physics involved in all aspects of tumbling! Enjoy!
-Laura, Kailey, & Jordan
Tumbling is best understood when it is broken down step by step, and while it may seem to defy the laws of gravity and physics, tumbling is in fact an excellent way to learn and understand the laws that govern this universe. However first the basic terms discussed must be defined so that the explanations are easy to read and understand.
Newton's Laws of Motion:
1. Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.
2. The relationship between an object's mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector.
3. For every action there is an equal and opposite reaction.
Conservation of Momentum:
"States that the total momentum of a closed system of objects (which has no interactions with external agents) is constant. One of the consequences of this is that the center of mass of any system of objects will always continue with the same velocity unless acted on by a force from outside the system." Equation: m1v1+m2v2=m1v1’+m2v2’
Conservation of Energy:
"It states that the total amount of energy in an isolated system remains constant over time (is said to be conserved over time). A consequence of this law is that energy can neither be created nor destroyed, it can only be transformed from one state to another. The only thing that can happen to energy in a closed system is that it can change form, for instance chemical energy can become mechanical energy."
Is the tendency of a force to rotate an object about an axis.
Moment of Interia:
Also called "rotating inertia" it the rotation that depends on mass distribution. Equation: I=1/2MR
Is the resistance of any physical object to a change in its state of motion. It is represented numerically by an object's mass.
Now to start explaining tumbling! If you are unfamiliar with what any of these moves looks like, our photo gallery has all the techniques described captured.
First lets take the easiest tumbling around, cartwheels! The cartwheel begins with the tumbler leaning forward and beginning to fall. The inertia carries him/her forward until their hands connect with the ground. Now momentum and angular momentum carry the feet over the tumblers head until they hit the ground. Newton's second and third laws are also displayed here. It's vital that you have enough force to go against gravity and push your feet off the ground!
Now lets move on to something slightly more difficult, a back-hand spring. To start, a person stands straight up, in this position he or she has potential energy. Next the tumbler swings his/her arms and pushes off the ground, enacting kinetic energy and Newton's second and third laws of gravitational and angular momentum. The force carries the tumbler backwards and gravity pushes her back towards the Earth. Now the tumbler is upside down and uses the momentum to push with his/her hands upwards to carry through and the torque force to keep their body spinning. Torque allows the body to continue spinning until the tumbler's feet touch the ground again and they have completed a back-hand spring.
Lets look at one more example, and this time we will explain a tumbling sequence, something like a round-off, back-hand spring, full. A sequence begins much like any singular tumbling action. However it takes more force and power to carry through with a sequence of tumbling. Usually tumblers get a running start building up the momentum that will help them later. Next the tumbler will usually do a round off to begin and afterward a back-hand spring. Momentum will carry the tumbler through the sequences and the continued application of Newton's Laws with equal and opposite force against the ground will keep propelling the tumbler forward. The end of this sequence, a full, is a little different than what has been discussed previously. A full is literally spinning in the air, and torque is the main force behind the spin. The angular momentum converts into torque and allows the tumblers body to spin as if spinning on an axis until they land again.