Projectile Motion

As was discussed previously, projectile motion in two dimensions will follow a parabolic trajectory path. This is precisely the path that a figure skaters body takes as they launch themselves through the air to execute a flawless jump, such as an axel or double flip. The start of projectile motion, or in this case, the start of a figure skaters jump will be called the launch. The angle θ above the horizontal x coordinate is called the launch angle. Throughout the jump, gravity acts downward on the skater so her vertical acceleration will be –g of free fall. In contrast, her horizontal acceleration will be zero. In terms of velocity, her vertical component of velocity will be constantly decreasing throughout the jump. If her vertical velocity is constantly decreasing, it is constantly changing and is thus the exact definition of acceleration (change in velocity over time). Her horizontal component of velocity will be constant throughout the jump because there is no acceleration in the x direction. To sum things up, during a jump, a figure skater will experience uniform motion at a constant velocity in the horizontal direction and in the vertical direction she will experience free fall motion.

Parabolic Trajectory path

Projectile Motion diagram showing both the horizontal Vx and vertical Vy velocity vectors as well as the vertical acceleration vectors

The skaters projectile motion below, follows the same exact curve as the one illustrated above

If we felt like getting more in depth...
We could actually calculate different components of a figure skaters projectile motion throughout a jump. By using the following equations of linear motion and projectile motion we could estimate how far he or she traveled in the x direction. We would simply need a little information, such as an initial x position, initial time, initial velocity and a launch angle. These equations would probably be the most helpful in calculating a figure skaters maximum height achieved during the projectile motion. This type of information would be really helpful for a skater that was struggling with completing the necessary rotations needed for his or her jump. Skaters frequently lose point for half completed rotations.

Home