UP News
James Stankowicz
Assistant Editor:
Steven Hochman
Layout Director:
George CB Ling
Online Editor:
Steven Hochman
Staff Writers:
Victor Albert
Brady Nash
Eric Swanson
Faculty Advisor:
Dr. Amlan Biswas

Physics of Phlips
by Harold Rodriguez

In order to fulfill the UPNews requirement of at least one comically misspelled word, we analyze the physics behind flips. If you want to flip a ruler, you apply a torque away from the spin axis (like its geometric center). However, this strategy doesn't work well when flipping yourself. How can you apply a torque to your feet, and/or head (in the opposite direction) strong enough to cause you to rotate? No, flips usually work by effectively changing your angular momentum via mass redistribution, not by applying big torques.

For a backflip, instead of kicking forward with your legs and pushing your head back, you must start by jumping *straight up* first. Counter-intuitive, yes, but here is where physics saves your neck. Before the push-off, throw your arms backward as you contract your legs. You're building all this potential energy in your legs to release in one large impulse. Now jump! As you gain height, swing your arms forward and upward, giving you even more lift. Since your arms have inertia, and since they extend radially from your body, they will also have a small backward component after they reach the vertical. As your body begins to slowly rotate backward, contrary to common sense, don't push your head backward! Tuck your legs inward towards your chest. This rearrangement of mass causes your body to spin since you're bringing mass closer to the spin axis. Of course, it takes some work to do so, which is why your abs will hurt from excessive backflipping!

Frontflips are based on inertia and manipulation of velocity components. Take a few bounds forward, gaining a considerable amount of horizontal momentum. Then, jump forward, trying to land at a 45 degree angle to the floor. The reason for this is illustrated in the diagram. If you wanted to change the direction of a tennis ball from horizontal to vertical by hitting it against a wall, how would you want the wall oriented? Forty-five degrees! So, after pounding the ground hard, a lot of your horizontal momentum should be converted into vertical momentum. Then, the inertia of your body's upper-half should be “continuing” it forward, despite your stationary lower-half, at which point a tuck will complete the frontflip. Hence, the move is almost self-performing (if you know and trust the physics behind it). With that said, I hold no accountability for any ways you may find to break your neck. Good luck!