Question

16. You are ice-skating. Explain the physics between the ice and the blade of your skate.

Answer 1

The gravitational force (weight) is acting on a very small surface area of the blade. This creates an extremely high pressure on the surface of the ice, enough to actualy melt a thin layer of ice. The coefficient of friction between the steel and the melted ice is even less than it is between steel and solid ice. A sharpened blade is slightly concave in shape, so each blade actually has two razor-thin edges, which helps to explain why a sharpened skate blade out-performs a dull blade, in which this concave shape is less pronounced.