The speed of a ski depends directly on the friction that the base has with the snow. The smallest amount of friction, the faster a ski can go. The force of friction is of course determined by a force coefficient multiplied by the normal force.

There are two types of friction. Kinetic friction and static friction. Kinetic friction is the friction when an object is moving. In terms of skis, this is when a ski is gliding along the snow. The other friction, is static friction. This is equally as important as kinetic friction in cross country skiing. Static friction is the force of friction on an object before the object moves.

The structure in skis can minimize this friction. To minimize friction, wax is applied to the base of a ski. The wax is used to melt a small layer of water between the snow and the base of the ski. This is what the ski glides over. When there is not enough water, dry friction is achieved. If this is the case, less structure must be used in order for the water to not wick away from under the base. If there is too much mater, there is wet friction. This creates the suction effect. If this is the case, more structure must be used to quickly get rid of enough water to let the ski glide easily.