Objective To explore the engineering design of ice skates, along with the scientific concept of conductors and insulators.
Materials Ice cubes, pennies, dimes, and plastic knives
Estimated Time 20 minutes (This is provided as a guide, as all activities can be lengthened or shortened as necessary).
CA State Science Standards 3rd grade I&E5e; 4th grade I&E 6c, d, f; 5th grade PS 1c and I&E 6g
Video Support Content None Available
The Science Metal is a conductor of heat, whereas a material such as plastic is not. The heat from your hand is transferred to the coins to melt the ice.
Student Activity One of the most unique aspects of the sport of ice hockey is the surface on which the game is played: the ice itself! Try this simple activity to learn more about why ice skate blades are especially engineered for different sports. What happens when you move the edge of different objects across the surface of an ice cube? First, press and hold the edge of each of the four objects listed below into a cube of ice. Describe whether the objects sat on top of the ice or dug into the ice.
Next, slide the edge of each of the objects across the surface of the ice cube and imagine that each edge is a skate blade. Describe how the different objects moved across the ice: did the tiny “blades” dig into the ice or slide easily across the surface? Did they leave a streak on the ice? [The pennies and dimes will dig into the ice, whereas the plastic knife edges will not.]
Object Observation Outside edge of a penny Outside edge of a dime Serrated bottom edge of
a plastic knife Smooth top edge of a
plastic knife
What do you think? Would (1) digging into the ice or (2) sliding across the ice give the skater more power? More speed? More control? Decide which of the above materials would make the best skate blade and explain why. [The skater will gain more control if the skate blade is able to grip the ice, however if the blade sinks too deeply into the ice, the skater loses speed. Therefore, ice hockey is played on very cold, hard ice to ensure speed, whereas figure skating is performed on cold, soft ice to ensure control for spins, stops and jumps.]
Are all skates the same? Visit The Science of Hockey Exhibit at Discovery Science Center to explore different skates and the movement of hockey players, figure skaters and speed skaters on the ice.
Hockey Skates Figure Skates Clap Skates Heavyweight blade extends past the Blade attached to the boot by a
boot. hinge at the front, so blade stays in Lightweight blades, curved at both Toe pick allows skater to dig into the contact with the ice longer. ends; ice for stops and jumps. This design lengthens the skater’s Comfortable padded boot. Boot is stiff to keep ankles and feet stride, distributing the energy of the
stable during jumps and spins. leg more efficiently.
Final Question The skate blades are mostly sharp with a smooth edge. The exception is the toe pick on the figure skater’s skate. The serrated edge of the toe pick helps grip the ice. Which objects used in the above activity had a serrated edge? [Hint: The dime and the plastic knife edge have serrated edges.]
Activity 1: The Design of Ice Skates
What happens when you move the edge of different objects accross the surface of an ice cube?
Object Observation
Outside edge of a penny
Outside edge of a dime
Serrated bottom edge of a plastic knife
Smooth top edge of a plastic knife
What do you think?
1) Would digging into the ice or sliding across the ice give a skater more power? Would a penny, dime or plastic knife make the best skate blade for power? Why?
2) Would digging into the ice or sliding across the ice give a skater more speed? Would a penny, dime or plastic knife make the best skate blade for speed? Why?