The Physics of Skiing

Date

2014-05-14

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Abstract

The purposes of these three experiments were to predict and analyze the physics involved in ski racing. The first experiment was to test the effectiveness of an athlete wearing a speedsuit to reduce air resistance and increase acceleration. This was done by analyzing video data from three different scenarios to compute and compare their accelerations. The scenarios and their respective accelerations were: standing up, jacket on, - 5.973 _ 0.1409 m/s^2 , tucking, jacket on, - 5.425 _ 0.1967 m/s^2 , and tucking, jacket off, - 6.830 _ 0.2532 m/s^2 . An effective value for the resistance coefficient was found with these values: 'k=-0.358. The second experiment was to calculate the tangential force on the ski of a racer making a carved turn and to show that a smaller angle between the skier's legs and the snow yields a larger force. Through freeze-framing a video, an image of the racer at the apex of the turn was analyzed along with the measured velocity of the skier. Two videos were analyzed, and one photo of a professional skier was analyzed for comparison. The first run by Rebecca Spitz was calculated to have a tangential force along the ski of 712.0 _2.4 N at an angle of 35_. The second run by the same athlete had a tangential force of 977.0 _1.09 N at 31_. The professional athlete chosen to compare to was Ted Ligety, and the tangential force along his ski was found to be 1890 _86 N at 22_. The third experiment was to calculate a pseudo spring constant for the ski that is representative of the stiffness of the core. The ski was allowed to oscillate, and the frequency was measured. The value for the stiffness was used to calculate the approximate restorative force of the bent ski. The value obtained for the stiffness constant s was s=5000 kg's^2 . The restoration force of the ski flexed to 0.04 m was 200 _0.01N.

Description

Thesis completed in partial fulfillment of the requirements for the Alfred University Honors Program.

Keywords

Honors thesis, Physics, Skiing, Sports

Citation

DOI