Science of NHL Hockey: Projectile Motion
Subject Area: Physical Science
Grade Level: 5–8 (Physical Science)
Lesson Title: Projectile Motion
National Science Education Standards:
 Science as Inquiry: 5–8
 Motions and Forces: 5–8
Suggested Prior Knowledge: concepts of velocity and angles; lab techniques of measuring
velocity and angles. Note that students might more easily grasp the concepts in this video if they
have already viewed the video Newton’s Three Laws of Motion.
Purpose and Introduction: This video uses the hockey technique of a wrist shot to give
students an understanding of the relation between uniform linear motion and uniform angular
motion, and how a projectile moves.
Key Vocabulary:
angular motion—movement of an object around a fixed point or axis.
angular velocity—the number of rotations an object makes around a fixed point or axis per
unit of time.
linear motion—movement of an object along a straight line.
motion—change in the position of an object with respect to time.
projectile motion—movement of an object through space along a path determined by an
initial velocity and the effect of gravity and air resistance.
Objectives:
1. Students will differentiate among three common kinds of motion in two dimensions.
2. Students will design and carry out an investigation to measure linear and angular
velocity.
3. Students will design and carry out an investigation to determine the shape of a
projectile’s path.
Materials:
- safety goggles
- 2 stopwatches
- tape measure
- small flexible tubing
- adapter to faucet
- nozzle
- catch pan (or sink)
- ring stand
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- clamps
- clear plastic sheet
- erasable marker
- paper
- pencil
Procedure:
1. Before students watch the video, ask them what projectiles are and how they might describe
the path of a projectile. Most will likely describe something like a bullet and a path that
shoots straight out, and keeps going. After students watch the video, lead a discussion in
which they can correct their own thinking about projectile motion. Have volunteers describe
the other kinds of motion in the video and compare and contrast them. Use questions such as
these to prompt discussion:
 What is an example of linear motion?
 What is an example of angular motion?
 What is a projectile?
 What path does a projectile follow?
2. Lab protocols should be followed incorporating safety equipment. Goggles must be worn at
all times.
3. Guide students to design an investigation that will allow them to observe the connections
among linear, angular, and projectile motion. Questions such as the following can help focus
students’ plans and guide them:
 What are the units of linear velocity?
 How do you measure linear velocity?
 If an object rotates around its axis once per second, what is its angular velocity in
rotations/second?
 How do you measure angular velocity?
 How can you record the path of a projectile?
 How can you measure the velocity of a projectile?
Comparing Linear and Angular Speed
4. One way students might explore linear and angular speed is with one student spinning slowly
in the center of an open space (a football field, for example). The student should make one
complete rotation every 12 seconds (one quarter of a rotation in 3 seconds, or 0.083
rotation/second). Make sure he or she does not get dizzy.
5. Then two students could link arms with the spinning student, one on each side, and walk in
small circles. Expand the line of students by having more pairs of students link arms, while
the student at the center spins at the same rate. One student with a stopwatch measures the
angular velocity of rotation. (Make sure that all parts of the line move with the same angular
speed f.)
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6. More students could link arms until the circle grows too large for the outermost students to
keep up easily (or no other students are available). Students should make two complete
circles at maximum size. The two outermost students should then break away from the others
and walk in a straight line at the same speed. (They may need to follow one of the lines
marked on the field.) A second student with a stopwatch measures the time they need to
cover a predetermined distance.
7. Measure the radius of the circle traveled by the students at the end of the line. Calculate the
speed of the outermost students using their angular speed, the radius of the circle, and the
formula v = 2πrf. Students compare the speed calculated for the outermost students walking
in a circle to the linear speed measured directly. (They should be equal).
Graphing Projectile Motion
8. Brainstorm ways with students that they might be able to document the path of a projectile so
that they could then transfer the patterns to graph paper. One possibility students might
envision is to connect tubing to a faucet to fashion a hose and clamp it to a ring stand near its
base. They can adjust the tubing so that it is pointed upward and produces an arc of the size
that would fit on a regular sheet of graph paper (about 20 cm wide and about 30 cm high).
Elicit from students where the speed of the water is greatest (at the bottom of the arc) and
where it is least (at the top of the arc).
9. Students could then clamp a plastic sheet vertically and align it close to the stream of water.
This allows them to trace the path of the water on the dry side of the plastic with the marker.
plastic sheet
ring stand
with
clamps
tubing
connected
to water
spigot
arc of water
catch pan
10. With the water off, students could attach a sheet of graph paper to the dry side of the plastic,
making sure that the paper is vertical. They trace the arc onto the graph paper. By folding the
graph paper students should be able to recognize that it is symmetrical. If they do not know
the name of the figure, remind them that the video identified the path of a projectile as a
parabola.
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11. To follow up this investigation, have students determine what initial angle for the stream of
water produces the greatest horizontal range. Have each group sketch all the paths they try on
a single piece of paper and compare its sketch to sketches by other groups. Then ask the
groups what angle a hockey goalie should use in order to get maximum range when throwing
a puck (The puck should leave his hand with a path 45 degrees from the vertical).
Additional Resources:
 http://www.korpisworld.com/Mathematics/diversions/activity_for_angular_velocity.htm
 http://www.uwstout.edu/physics/upload/UNIFORM-CIRCULAR-MOTION.pdf
 http://www.srri.umass.edu/sites/srri/files/mop_samples/ActAT016.pdf
 http://teachingphysics.wordpress.com/2009/03/01/projectile-motion-activity/
 http://www.srri.umass.edu/sites/srri/files/mop_samples/ActAT009.pdf
 http://jersey.uoregon.edu/vlab/Cannon/
 http://pdgusers.lbl.gov/~aerzber/aps_motion.html#projectile
 http://www.livestrong.com/article/447525-projectile-motion-of-golf-balls/
 http://mrfizzix.com/basketball/index.htm
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Student Worksheet for Projectile Motion
Experiment Title: _____________________________Date: __________Name: _____________
Student Hypothesis: _____________________________________________________________
Materials: _____________________________________________________________________
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Wear safety goggles for all lab work.
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Data and Observations:
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Analysis of Data: _______________________________________________________________
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Conclusion: ___________________________________________________________________
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