# Skating on slippery ice

## TL;DR

This paper investigates the friction of a skate on ice, focusing on how a thin water layer affects friction, revealing that the combined effects of ploughing and sliding lead to weak dependence on velocity and temperature.

## Contribution

It presents a unified theory combining two conflicting models to explain water layer formation and its impact on skate-ice friction.

## Key findings

- Friction is insensitive to velocity and temperature due to pressure adjustments.
- High velocities increase pressure, reducing contact area and friction.
- The theory reconciles previous conflicting models on water layer formation.

## Abstract

The friction of a stationary moving skate on smooth ice is investigated, in particular in relation to the formation of a thin layer of water between skate and ice. It is found that the combination of ploughing and sliding gives a friction force that is rather insensitive for parameters such as velocity and temperature. The weak dependence originates from the pressure adjustment inside the water layer. For instance, high velocities, which would give rise to high friction, also lead to large pressures, which, in turn, decrease the contact zone and so lower the friction. The theory is a combination and completion of two existing but conflicting theories on the formation of the water layer.