How fast can a professional hockey player skate on ice?

Answer: About 20 mph, due to the air resistance for the average player.

The speed of a hockey player depends air resistance. Imagine that all players were the same in size, shape, and strength, and skated on ice at the same temperature. The faster a skater skates the more will be the air resists to his forward motion. If all factors are the same, the air resistance to the player's forward motion will increases with the "cube" of his speed. For example, if a player wanted to skate twice as fast he would need to overcome the resistance of air that would be two times two, times two, times two, (2 X 2 x 2 = 8), or eight times.

The speed of a hockey player is just one skill he needs. He needs to be agile for quick turns, always be balanced on his skates, and know where to be skating to win the game. Playing smart is more important than just speed alone.

The energy in wind is also proportional to the cube of the wind's speed. For example, a wind that picks up speed from 10 mph to 30 mph will have increased in speed to three times faster, but the wind's energy will have 27 times more energy: 3 x 3 x 3 = 27. 

The power in wind being related to the wind's speed cubed is the principle that causes a jet plane to take off. A modern jumbo jet weighing 110 tons takes off at 180 mph where the air pressure under its wings has the sufficient lift.

 The power of an electric windmill works the same. An increase in wind speed from 10 mph to 30 mph creates three-cubed-times the electric energy, or 27 times more electricity.