The Science Behind Alpine Skiing & Hitting Top Speeds Hucksters

Skiing and Gravity

Skiing is all about manipulating forces, most importantly of all, gravity. Gravity is the force that pulls us towards its centre, although the earth’s crust stops us getting any further than the surface!

Tip the earth, so it is at a sharp enough slope, and you have mountains. Gravity is still pulling us towards the ground, and the angle means we slip and slide down unless we put in the active effort to resist the earth’s gravitational pull. Throw in the slippery surface of the snow, and it makes it even easier to glide down the planet, closer to its centre.

Add slippery sticks to our feet to reduce friction between our feet and the ground, and push forward with your sticks, and suddenly we have a gravitational force pulling us down and motion propelling us forward. The less friction, the steeper the slope, and the faster we push forward, the faster we alpine ski!

Centre of Mass and Base of Support

The Centre of Mass is the three-dimensional balance point of an object. The centre of mass of your ski pole is likely in the middle leaning slightly closer to the handle because that side is heavier. Likewise, for humans, our centre of mass is somewhere in our core area, varying depending on our body type. However, humans have moveable body parts, so our centre of mass changes depending on what position we are in. If we bend at the hip forward, our centre of mass moves forward. If we turn at the ankles, this force is even more dramatic.

Our base of support is what the snow pushes back on to keep us on the earth. Just as legs support a chair, our feet support our bodies in day-to-day life. On the slopes, their skis support each skier. If our base of support fails to support our centre of mass, we go tumbling!