Friction on Ice

Friction occurs even on smooth surfaces such as ice, otherwise skating on ice would not be possible. When a figure skater skates on ice, it is the friction between the inside of the blade and the ice which causes the resistance that allows for motion in the opposite direction, propelling the skater forward.

Moment of Inertia (cont)

The moment of inertia depends on both the mass of the object and the distribution of this mass around the axis of rotation. For this reason, figure skaters often pull their arms in during a turn in order to decrease their moment of inertia and increase their speed.

Motion Resistance

A spin performed by an ice skater is the result of more than just torque. Inertia, the skater's bodily resistance to a change in state also comes into effect by decreasing the speed of the skater. In situations such as making a turn while ice skating where the motion is rotational, this factor is called the "moment of inertia."

Skating on Ice

Torque is what allows a figure skater to skate on ice. A skater pushes one of his/her feet against the ice in order to exert a torque on his/her body and thereby initiates a spin.