Alpine skiing is one of my favorite things to do. And in thinking about the sport there is a lot of physics involved! Downhill skiing involves gravity and friction more than any other sport I can think of. The most important equipment to any ski racer is their skis, this involves an amazing amount of maintnance. Taking care of a good pair of race skis includes sharpening them after each use and waxing them as well. Waxing skis has a lot to do with the physics of the sport. What waxing does is it fills in all the little scratches and grooves worn into the skis which are unavoidable after use. Having these little grooves filled in provides the racer with the smoothest surface possible for the ski to travel over the snow, and the smoother the ski, the faster it will carry the skier.
sharpening skis also has a lot to do with the physics of the sport. While waxing the skis is an effort to reduce friction, sharpening skis is an effort to induce more friction. around a turn the edge of the skis is responcible for holding the full force of a skier while at the most powerful part of the arc of the skiers path. Around any turn in a race coarse a skier can withstand up to 4G of force at high speed, and all that force is deflected straight to the edge of the skis which in turn must be able to grip the snow well enough to keep the shape of the arc turn while under force.
this diagram shows the different forces applied to a ski racer going around a turn in a race coarse:
An interesting experiment occurs during almost ever race ive ever been to. you can always tell who doesnt take care of their skis by how they preform on the icy coarses. someone who doesnt bother to sharpen their skis can end up sliding around the turns instead of being able to cut into the snow to bend the ski into a nice arc shaped turn. overall, the sport of alpine skiing involves an incredible amount of physics, I wonder what aspects of other sports involve a lot of physics?