Friction and skating forces on an ice rink –

- During a game the hockey players as well as the refs will wear hockey skates. Figure skaters will wear a different kind of skate with a sharp picked object on the front of their blade that allows them to utilize their kinetic energy and lift off the ice into a rotational motion. The ice provides a frictional surface such that a player may use his skates to glide around but have enough control to not let his feet fall out from underneath of him. A shoe is much harder to move on and glide on. The surface of a shoe is much broader and the material in the sole of the shoe has a lower friction coefficient and does not offer much control. It’s similar to how a car slides on ice with rubber tires. An ice rink is kept smooth by a vehicle called a zamboni. The ice is flooded with water and smoothed out so it becomes more frictionless. If a car were to drive on a smooth ice rink, it would be very hard to have any control. Imagine a thin lair of snow on a road, dump water on it, and allow the water to freeze; it’s impossible to drive safely on!

- If you have ever watched a hockey game, you might hear the players say the ice is “fast” or the ice is “slow” as they talk to the commentators. In terms of physics, the ice is at a temperature that changes the action and reaction forces between the ice surface and the players’ skates. The interaction between the blade and the ice creates heat by the friction created. This interaction makes a thin lair of water underneath the skate and allows skaters to glide on the ice. Ice on a microscopic level is made of tiny bouncing atoms. Although the atoms are not bouncing around very much they are still bouncing around. When they have energy added to them, in this case friction, they begin bouncing even farther apart, and this is where the water comes from. When you cut the out some of the friction, the skater will be able to even faster! There have been ideas of having a heated blade. It is like cutting butter with a hot knife. If the knife isn’t hot, the person cutting has to exert more force down on the butter.

- Forces being exerted when someone skates:

1. The way a player skates he pushes off the ice at an angle. Now when you see this the way the arrow is going, you think well that doesn’t make sense; but it does because there is an opposite and equal reaction of the ice pushing back on the skate (Newton’s third law). This law allows the skater to move forward.

2. The normal force is pushing back on the skate and it is greater than the force being exerted downward.

3. Friction is putting a force backwards on the skate.

4. There is a force downward that everyone feels and in this case it’s the weight of the skate multiplied by the acceleration of gravity (in general it’s 9.81 meters per second to the second power).