Why is snow slippery?

Water is one of the most interesting physical phenomena, able to take several forms. When the air temperature reaches 0 degrees, it turns from a liquid into ice. A snowflake is also ice, which has a crystalline form. With the coming of winter, snow covers huge areas of the surface of the globe. It has a great influence on the whole planet and itself has interesting properties. For example, the white winter cover can be slippery. Sometimes pedestrians, cars and quad bikes feel this for themselves. So why is snow slippery?
What causes the slipperiness?

Snow is not just an occasion for children's winter games, but also an amazing phenomenon that influences our whole life. It is very cold in winter, and to a large extent this is because the light snow cover reflects the sun's rays, which are able to warm the globe.

Causes of the slipperiness

1. The pressure exerted on snow lowers the melting point of ice. Under pressure ice can melt even at low temperatures (below 0 degrees). This is because water expands when it freezes, while pressure opposes this expansion, and therefore the freezing as well.
2. When friction arises, as a sledge or skis move over the snow, heat is released. Because of this the ice begins to melt, and a “water film” (lubricant) appears, which is what causes the sliding. Friction also depends on many factors: on the size of the sliding surface – the larger it is, the greater the friction, on the temperature of the snow, on the material of which the skates or skis are made, and on the speed of movement.

It is precisely thanks to the sliding that fast movement over snow cover becomes possible with the help of sledges and skis. The sliding effect is the reason for the fact that travelling on a sledge takes 10 times less effort than moving on wheels.