Our PBL Project

Driving Question

How does angular momentum affect the velocity of an ice skater when he or she spins?

This video explains simple but useful concepts that lie behind figure skating. The angular momentum and the center of mass defines the spins in the ice skating world. The following video explains these concepts and gives amazing visuals on up close and popular movements in ice skating with the physics behind the incredible sport.

Introduction

There are a lot of concepts that surround the sport of ice skating. Practically all of the concepts in the sport of ice skating involve physics. In this project, we are going to discuss some principals behind ice skating that essential to the understanding of physics. The most principal concept is how friction works on the ice. Another concepts are angular momentum when spinning and Newton's Third Law of Motion when jumping. Also, there is the concept of Inertia is present in ice skating for the explanation of skates' blades against the ice.

Purpose

To explore the physics of ice skating and for an understanding of why ice skating is possible from a Physiscs point of view. WE hope to make discoveries and ourselves and to share what we have learned with others.

Materials

  • Camera

  • Skates

  • Video Camera

  • Windows Media Player

  • Ballistic Cart

  • Ice Skater

  • Spinning chair

  • Weights

Procedure

In order to effectively show the demonstrations of angular momentum, we will have an experienced ice skater demonstrate spinning on a an axis on one foot, she will explain the basics of spinning and the location of the center of weight which is on the hips. She will be showing the effect of her arms being spread out in relation to haw many radians per second she spins. The other person will take a video of the skater to analyze the effect of rotational inertia. This will explain the equation of Conservation of Angular Momentum. I1W1=I2W2. The skater will demonstrate how rotational inertia decreases as rotation speed increases. But, when rotational speed increases, rotational inertia increases. When she is spinning, there are barely any outside forces that affect the spin. Pulling her arms in will reduce her rotational inertia causing her to spin faster. This will also be explained with an spinning chair and weights. As one pulls in their arms, the chair will spin faster, because their rotational inertia will decrease.

For us to be able to show projectile motion we will demonstrate the physics behind it first with a ballistic cart. We will show that even though one object is thrown in the air they will both meet at the same point and at the same time. Then we will show a video of the exact same principles in ice skating when a female ice skater is thrown in the air by a male ice skater. Furthermore we will show diagrams with the skaters velocity at various points in her arc from her jump. This will also demonstrate the physics of projectile motion, and explains why the skater make an parabolic. We will explain the concept of two motions. One will be constant moving up the x axis. The y axis will change over time becasue of gravity.

Scientific Principle/Essential Understanding

Angular Momentum and Conservation of Angular Momentum

    • Source From: Mandanas, Laura. "Notes From A Queer Engineer: Yuna Kim And The Physics of Figure Skating." Autostraddle. The Extitant Group at LCC, 2009. Web. 21 Sept. 2014.

Inertia: Object stays in motion unless acted on by a force. Ice skaters stay in motion unless the blade or another friction is acted upon the skater.

Friction: A resisting force that is acted upon when two objects slide against each other. In this case, it is the skates and the ice.

3rd Law Law Motion: For every action, there is an equal and opposite reaction. The force put upon the ice by the skate propels the skater to jump upwards.

Projectile Motion

Source from: Mandanas, Laura. "Notes From A Queer Engineer: Yuna Kim And The Physics of Figure Skating." Autostraddle. The Extitant Group at LCC, 2009. Web. 21 Sept. 2014.