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Physics in Skateboarding: The Ollie
The Model
Diamonds 22

Click this link to view a model of me performing the ollie.

This model illustrates all the forces involved in the ollie. As I begin to ollie off the ledge I am moving at a constant velocity. I slam the tail of the skateboard into the ground causing the ground to impart a force on the board making it accelerate upward. Then I slide my foot up on the grip-tape to even out the board. After I reach maximum height, gravity pulls me back toward the ground. I then prepare for impact, and I bend my knees to absorb the force of the ground pushing up on the board after landing. Finally, I continue to ride away with a constant velocity.

Model Problem: If my velocity at the beginning of the ollie was 5 meters/second, the drop from the ledge to the bottom of the stairs is 1.6 meters, and I ollie up at an angle of 6 degrees, then how far did I go during the ollie off the ledge?

modeldiagram3.jpg

Solution: Since you know the angle and the magnitude of the launch, than it is possible to use trigonometric functions to solve for the magnitudes of the x and y velocities. Vy= .52m/s  Vx= 4.97 m/s
     X-Variables                       Y-Variables Up                  Y-Variables Down
Vo=4.97 m/s                          Vo=.52m/s                         Vo=0
V= 4.97 m/s                           V=0                                   V=?
A= 0 m/s^2                            A= -9.81 m/s^2                   A=9.81m/s^2
T= .458 sec.                           T=.053 sec.                       T=.405 sec.
ChangeX=2.28m                    ChangeY= .014m                ChangeY=1.614m
 
Using the big 3 equations we can solve for the unknown variables.
 
From this data we see that I traveled 2.28 meters during the ollie off the ledge in the model.