Friction and collisions are concepts relevant to both ice hockey and figure skating. Consider the graph below, excerpted from a book by Schottenbauer Publishing:
Discussion Questions
How is air hockey similar to ice hockey? How is it different?
How is air hockey similar to ice skating? How is it different?
What happens when a hockey puck collides with a stick?
How are the phenomena in this graph similar to collisions between an ice hockey puck and stick? How are they different?
What is the role of friction in ice skating? What does friction do to the motion of a hockey puck or a skater?
How does this graph demonstrate friction?
How are the phenomena in this graph similar to friction experienced by an ice hockey puck? How are they different?
How are the phenomena in this graph similar to friction experienced by an ice skater? How are they different?
Additional sample graphs are available in a free pamphlet from the publisher's webpage.
What types of measurements are ideal for understanding ice skating? Take a moment to write down a list of at least four types of data to collect and compare. What types of equipment are necessary to measure each type? What physics concepts are relevant? Many types of interesting data are available for comparison in the book The Science of Ice Skating: Volume 1 (Extended Edition) from Schottenbauer Publishing. Data include position, velocity, acceleration, and force for the following equipment:
Surface Types
Ice
Synthetic Ice
Wet
Dry
Skate Types
Bob Skates
Child Double-Runner Skates
Hockey Skates
Youth
Adult
Figure Skates
2 Sizes
2 Types of Blades
Blade Preparation
Sharpened
Unsharpened
Skate Mass
None
Added 2.5 pounds of weight
Additional types of data include:
Hockey Puck Motion
Vertical Motions (Force)
Stepping
Jumping
Skate Support for Ankles (Force)
Ice Melting (Temperature)
Free sample graphs are available in a free pamphlet from the publisher's webpage.
A new video from Schottenbauer Publishing analyzes four spins with graphs. These include three forward spins (centered, centered with step out, and traveling), and a back spin (centered). The video is available on YouTube.
Two graphs from the video are shown below:
Discussion Questions
What body part is most likely traced in the video?
Using a ruler, estimate the center of each spin on its graph.
How many times does the skater revolve in the first graph? In the second graph?
What would a traveling spin look like on a graph?
Additional free graphs are available in a free pamphlet from the publisher's webpage. The following books from Schottenbauer Publishing contain similar types of graphs and data pertaining to the science of ice skating, figure skating, and hockey:
Which body part moves the most in the x direction? In the y direction?
What is the name of this move?
Now, consider the following pictures, excerpted from the video. (This move is shown in the YouTube Video Cool Skating Move.)
Discussion Questions
Is this move in the first or second half of the graph?
What is the primary motion which occurs between these two pictures?
What concept(s) from physics are relevant for this move?
Is this move found in (a) figure skating, (b) ice hockey, or (c) both?
The diagram below highlights the move on the graph.
Discussion Questions
Which body part moves the most during this segment of the graph?
Which body part moves the most in the x direction? In the y direction?
Additional free graphs are available in a free pamphlet from the publisher's webpage. The following books from Schottenbauer Publishing contain similar types of graphs and data pertaining to the science of ice skating, figure skating, and hockey:
Acceleration is an important feature of all ice skating. The same as with motion, acceleration can be translational (in a straight line), or rotational (in a circle). If acceleration is rotational, then it is in an axial direction, pointing inward to the center of the circle of motion. This form of acceleration is called centripetal acceleration. Consider the following graph, excerpted from The Science of Ice Skating: Volume 3 from Schottenbauer Publishing. The graph shows acceleration during a figure skating spin.
Discussion Questions
Initially, which direction is vertical or nearly vertical?
At the end, which direction is vertical or nearly vertical?
Describe the relationship between the initial and final angles of the foot in relation to the floor.
Is it possible to identify how many revolutions are present? If so, how many? If not, why?
Is it possible to determine whether this is a slow or fast spin? If so, which is it?
What is the initial velocity? The final velocity?
What is most likely the cause of the spikes in the graph?
Additional free graphs are available in a free pamphlet from the publisher's webpage. The following books from Schottenbauer Publishing contain similar types of graphs and data pertaining to the science of ice skating, figure skating, and hockey:
Synthetic ice is a popular, low-cost alternative to real ice rinks. Available in several forms and quality levels, synthetic ice usually consists of a slippery plastic surface which mimics the performance of real ice.
Compare the force line in each graph, using words. What is one major qualitative difference between the graphs?
In the second graph, what is the minimum force? Is the real force ever less than 0? Why or why not?
Why is force applied before the skate moves? Does this force contribute to velocity? At what point does force contribute to acceleration and velocity?
In the first graph, what is the maximum force? The maximum position? Velocity? Acceleration?
In the second graph, what is the maximum force? The maximum position? Velocity? Acceleration?
In each graph, calculate the range of time in which skate movement occurs. Which is larger?
The second graph claims that the skate has been pulled 1 meter. What is the evidence for or against this assertion? (Hint: How long is the skate?)
What force is required to pull the skate 1 meter on synthetic ice? On real ice? Which force is larger?
The following books from Schottenbauer Publishing contain similar types of graphs and data pertaining to the science of ice skating, figure skating, and hockey:
A simple demonstration of one type of synthetic ice is available below, in the YouTube video My First Ice Rink. This synthetic ice consists of High Density Polyethylene (HDPE), one of the least expensive surfaces manufactured in the USA. In fact, 3/16" x 48" x 96" HDPE sheets from US Plastics Corporation sold for approximately $2 per square foot in 2014.
While high-quality synthetic ice may cost $16 per square foot or more, one variety of Ultra-High Density Polyethlene (UHDPE) is available low-cost from Dezhou Shengtong Rubber & Plastic Co., Ltd. in China. According to price estimates in February 2015, an Olympic-sized synthetic ice rink (100x200 ft, UHDPE with sideboards) is available from China to East Coast USA w/shipping (not including import tax) for only $22,000!
Additional videos demonstrating HDPE synthetic ice are available on the Skating Science Playlist.
The concept of friction is essential to all skating on ice, whether it is for hockey, speed, or figure skating. Ice provides a reduced-friction surface, which allows humans to glide, rather than stick to the floor. Synthetic ice, consisting of slippery plastic, also reduces friction. The friction of synthetic ice can be lowered further by applying soapwater, or other slippery liquids. For gliding motion to occur, two types of friction must be overcome: initial non-moving (static) friction, and moving (kinetic) friction. The following graphs, excerpted from Volume 1 of The Science of Hockey, show the effect of force on motion of an official hockey puck.
Discussion Questions
Describe the magnitude of each force in Graph 1. For what amount of time is each force applied?
Describe the motion of the puck in Graph 2, using words.
How far does the puck travel? In what direction?
Are the graphs coordinated in the time dimension?
The following graphs, excerpted from Volume 1 of The Science of Hockey, compare the force required to move two types of pucks on synthetic ice (HDPE plastic).
Discussion Questions
Is the total force different in these two graphs? If so, why?
Is the initial force different in these two graphs? If so, why?
What is the average force is applied to each puck?
Calculate the work involved for each puck.
Why does the practice hockey puck perform differently on synthetic ice than an official puck? (Hint: The practice hockey puck is normally used on concrete floors.)
Additional free graphs on the science of ice skating are available in a free pamphlet from the publisher's webpage. The following books from Schottenbauer Publishing contain similar types of graphs and data pertaining to the science of ice skating, figure skating, and hockey:
What happens when an ice skater jumps? The answer can be modeled in various levels of difficulty. One the simplest level, assume that the skater is simply a point mass object, without movement within the body. In this analysis, acceleration occurs in three planes, leading to changes in altitude and rotation.
On the most complex level, the skater's body must be analysed as separate components moving in relation to the center of mass, which for most humans is approximately in the center of the abdomen or hips.
Discussion Questions
What everyday motions are related to skating?
If skater motion were to be studied by making comparisons between graphs, which types of motions should be compared?
The following two graphs are excerpted from Volume 4 of Glide, Spin, & Jump: The Science of Ice Skating. Notice that these jumps, completed in a purely vertical direction on land, are simpler to analyze, because they lack the horizontal translational motion across the ice.
Discussion Questions
What are the major differences between these graphs?
In these graphs, how
can direction be determined? What direction is up?
In each graph, what
occurs in the vertical
direction?
In the lower graph, what
is the pattern of acceleration in the horizontal plane during the rotations?
In each graph, what sort of tilt (side to side) occurs?
Is it better to locate the wireless device on the stomach or chest? Why?
Describe the role of knee motions during each of the above jumps, and their effects on acceleration.
What is the role of non-relevant movements (such as the motion of breathing) in these graphs, if any?
What is the role of error or random motion in these graphs, if any?
Are these clean (technically correct) jumps? If not, what would the acceleration pattern be during a clean jump?
What would a fall look like in a graph of acceleration?
What would the graphs look like if the jumps were completed on the ice?
Additional free graphs of ice skating are available in a free pamphlet from the publisher's webpage. A humorous cartoon animation of an ice skater, showing approximate force vectors, is available from the publisher's YouTube channel.
The following books from Schottenbauer Publishing contain similar types of graphs and data pertaining to the science of ice skating, figure skating, and hockey:
On the surface level, both the technique and beauty of ice skating can be described by geometry, in terms of the angles of knee bends and arm positions. On a technical level, geometry is essential for understanding the science of ice skating, including the physics of force and motion. The books The Geometry of Winter Olympic Sports and The Geometry of Figure Skatingcontain diagrams which introduce children and teens to the task of identifying angles in ice skating. Consider the diagram below, excerpted from page 25 of The Geometry of Winter Olympic Sports (Copyright 2014, All Rights Reserved).
Discussion Questions
How many angles are formed in this diagram?
From a casual analysis, what types of angles (Acute/Obtuse/Right) are located in the diagram? Indicate the location of each angle.
In order to analyze the angles in this diagram, where should the coordinate axis be placed? Why? Is it necessary to identify more than one coordinate axis? Why or why not? If so, where should the axes be placed?
Using a protractor, measure all the angles in the diagram that are relevant to the art or physics of skating.
Is it possible to identify the direction of motion from this diagram? Why or why not?
Is this a figure skater or a hockey player? Justify your answer.
Assistance answering some of these questions may be found by watching the video How to Use Geometry Workbookson the publisher's YouTube channel. The following books from Schottenbauer Publishing contain geometry diagrams relevant to ice skating, figure skating, and hockey.
In elementary school, math students learn the graph-reading skills. How often do these same students enjoy applying math to real-life data? In books from Schottenbauer Publishing, students have the opportunity to decode graphs showing movement during popular sports.
What is the range of each variable in each graph? Include x, y, and t as variables in your analysis.
In this sample, which leg is used for pushing off? Which leg moves forward first?
Use the information from the graph to draw the body in physical space, at a minimum of 4 time points.
Is the right knee ever in front of the right hip? Is the right ankle ever in front of the right knee or right hip? Describe the sequence of motion.
Is the left knee ever in front of the left hip? Is the left ankle ever in front of the left knee or left hip? Describe the sequence of motion.
Additional free graphs are available in a free pamphlet from the publisher's webpage. The following books from Schottenbauer Publishing contain similar types of graphs and data pertaining to the science of ice skating, figure skating, and hockey:
