With the Winter Games coming to Prince George, it is interesting to talk about how much science is involved in sports - especially winter sports.
Everything from nutritionally stringent diets to the latest advances in material science to the inclusion of a sports psychologist as part of an athletes core team finds a place in elite athletics. High level athletics is a complicated business.
At a fundamental level, most sports rely heavily on scientific principles. Take downhill skiing as an example. In principle, its a relatively simple sport - you just stand on a couple of boards and slide down a slope at ridiculously high speeds.
But science is involved in everything from the modern lightweight, durable materials used to make skis, poles, and boots to the engineering of the bindings which allows them to release when necessary and only when necessary. With the punishment delivered during a two minute descent during a Slalom, Giant Slalom, or Super-G event, releasing only when necessary is a major concern.
Modern video equipment and the slow-motion capture technology used in televising modern sports provide shots of skiers carving corners. It is graphic evidence of the punishment that both equipment and body go through in competitive skiing. Indeed, in any form of skiing, it is amazing the forces and flexing that occurs.
At an even more fundamental level, though, the most important science for a downhill skier is the physics - the physics of falling and the physics of friction. When I say falling, I dont mean falling over on the slopes - although that can happen and can be quite painful as some of our athletes will attest.
No. From a physics point of view, the forces involved in skiing down a slope are the force of gravity, which pulls or accelerates the skier down the slope, and the force of friction which counteracts gravity and slows the skier down.
The impetus for getting from the top of a hill to the bottom is nothing more than gravity. Mass and gravity equal acceleration.
Downhill skiing is a process that can be best described as a controlled fall. This, of course, is why good skiers ski the fall line, which is the direct line that any falling object will take down the hill. It is the line that mogul skiers such Alex Bilodeau and Justine Duforu-Lapointe ski at the Olympics.
Of course, it is a little more complicated than this.
For example, the acceleration due to gravity should result in a skier's velocity perpetually increasing. But even speed skiers - the ones with the crazy helmets, the spandex suits, and the oversized skis - can only reach speeds of 200 kilometres per hour. This is their terminal velocity, which is the fastest speed that is possible for them to go.
The reason for this terminal velocity is, in part, friction in the form of air resistance - maybe air friction would be a better term. Any object travelling through the air must move the molecules of air out of the way and this requires energy. The energy required to cut through the air takes away energy from the forces that are pulling the skier down the slope.
In addition, the molecules of air also clutch and grab at the skier, resulting in drag. Reducing the drag is why skintight clothing is all the rage. Loose clothing would slow a skier down.
It is the sum of air resistance and friction between the skis and the snow that results in a terminal velocity for skiers. A skier can only accelerate so much.
Friction is also important in other aspects of skiing. It is friction between the skis and the slope that allow a skier to turn, to hold an edge, to handle moguls, or even flat groomed runs. If the skis dont grab the snow, or the snow the skis, then a wipe out occurs.
For the cross country skiers, friction is even more important. The right type of wax can allow a cross country skier to actually climb a slope.
Wax is simply a long chain hydrocarbon that interacts with the atoms and molecules on the surface of the ice crystals that make up the snow. These molecular interactions allow the skis to grip the snow rather than just sliding past. The right type of interaction is critical for cross country skiing which is why there are so many different types of wax and why so much care is employed in getting ready for the Winter Games. But even for cross country skiers, going down a slope is still a matter of falling down an inclined plane.
Falling and friction - these are the forces behind skiing. Understanding physics can result in a gold medal performance. The skiers with the right combination will be bringing home the medals from the Winter Games.
