Yesterday I went skiing for the first time (and no, I did NOT look that cool). And somehow as I was going down the slopes (very VERY slowly with lots of falling involved), I realized there's a LOT more physics going on that one would think initially.
For one, there's a LOT of friction problems. Obviously the goal of most skiers is minimal friction, and therefore go faster! However that was NOT my goal, considering speed led to panic which lead to crazy turns which lead to the unavoidable fall. So my goal was to maximize friction.
The easiest way to do this is to make a wedge and to turn a lot--go across the slope at small angles rather than straight down. This helps for obvious reasons; with the wedge, the edge of your skiis dig into the snow more, causing more friction and removing some of the slick, waxed surface area from the low-friction snow. The turns are a little more complicated, considering you can go QUITE fast if you do them a certain way. However in a sense the concept of using turns to go slow is simple; the ground you cover when you go down a slope in wide turns is less than if you were to go straight down. Energy is expended on turning, and friction is increased by going more sideways (using more of the edge of the ski than the waxed bottom) rather than going strait down.
There's a lot more physics involved when you look at moguls, jumps, and even the design of the skis themselves. However, considering I've only gone once, I'm going to leave an analysis of that up to the experts.
Friendly ski tip to beginners: NEVER fall backwards downhill on your skis if you can avoid it, you will NOT stop going down the slope