TENNIS
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Overview
Did you know that when Sloane Stephens unleashes her powerful
forehand, Sir Isaac Newton and his Second Law of Motion are there to
make sure the force of her racket acts on the mass of the ball to create
maximum acceleration and a winning shot? Sloane realizes that paying
attention to science and math can give her a competitive edge on the
tennis court, and now you can do the same!
Have you ever wondered why a tennis player puts spin on a ball? Why
tennis courts are made with different surfaces, or even why a tennis
ball is covered with fuzz? Did you ever think it might have something
to do with lift, drag, friction, or gravity? Have you wondered if math
and science power the game of tennis? Let’s find out.
Start by reading about the tennis-related science principles that
can make you a better tennis player. If you want to hit a forehand
like Sloane, learn how aerodynamics (the way objects move
through air) can help you control the speed of your shots.
When you’re ready to take what you’ve learned out for a spin,
ask friends or family members to try some hands-on activities
where they can Play the Angles, Build a Kinetic Chain and
Transfer Energy. Together you will learn how science and math
assure you have an advantage in your next tennis match.
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Play the Angles
Materials
“Tennis Court graph paper”, pencil or pen
Set Up
Print out several copies of the Tennis Court graph paper, provided below.
The graph paper has the diagram of a tennis court outlined within the squares.
You can also laminate this paper for reuse with dry erase markers.
To Play
Give each student a sheet of graph paper. Ask students if they have ever thought
about how you can use math to hit a winning tennis shot, to think about the “shape
of your shot”. Explain that geometry is a branch of mathematics that studies
shapes. Angles are a building block for creating shapes. In tennis, if you analyze
the relationship of one player to another and the placement of the ball, you will
see this creates the shape of a triangle. A tennis player can use math skills and
angles to pull an opponent off the court allowing them to place a winning shot.
Have two people “play a tennis point” using the court graph paper. One player is
player “x’ and the other is player “y”. The offensive player begins, they call out,
for example, “I am player “x” and I am hitting a forehand from the baseline”.
Then they put an “x” in the box where they stand to hit their shot. Player “y”, the
defensive player, decides where they would move to receive the shot. Draw the
angle that results from the position of the two players. Then, look at the angle
that is created by the forehand and count the number of squares on the graph
paper that are available for the ball to land. Did the defensive player make a good
call by coming to the net?” What would be the difference if the player returned
the shot from the baseline? Count the squares on either side of player “y” to
draw a conclusion. As students play additional points you can increase the level
of discussion about math by discussing angles of attack in tennis or how a cross
court shot creates the hypotenuse of the triangle. Suggest that students reread
the Geometry principle and think about playing the angles the next time they are
on a tennis court.
Extend the lesson: Ask students if they have a favorite tennis player. Suggest
that they watch that player and use their court graph paper to graph the way that
player plays a point, how they hit and receive a ball. Graph their movement on the
court and see if you can chart their strategy. How did they play the angles of the
court, both offensively and defensively.
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TENNIS
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Build Your Own Kinetic Chain Reaction
Materials
Foam ball(s), sheet of paper showing suggestions for the steps in a kinetic chain,
blank paper, pencil or pen, set of dominos
Set Up
Set up a row of dominos that can fall against one another (representing
a chain reaction). Print out the page of suggestions for steps in a chain reaction.
Cut out each step and mix the pieces of paper up on a table top. Provide blank
paper, pens or pencils that students can use to record the steps in their kinetic
chain. Place foam balls on a table.
To Play
To begin, show students the standing row of dominos. Ask one student to push
the first domino over. Tell students that when one domino causes all the other
dominos to knock into one another and fall over, they are seeing energy
transferred from one domino to another through a chain reaction. Ask students if they have ever seen energy transferred through a chain reaction in any
sport. Tell students that in exercise and in sports parts of your body; your muscles,
joints and nerves, link together to create motion, to create chain reactions. Kinetics is
the science that studies how force can create or alter motion. When we link motions
it is called a kinetic chain reaction. Science moves our bodies.
Ask students if they would like to make their own chain reaction. Hand a foam ball to the
students who want to participate. Tell them that they are going to see who can throw their
ball the highest by creating the most effective kinetic chain reaction. Tell students to use
the provided paper to record their trial and error and the steps in their kinetic chain.
Direct the students to look at the eight suggested links on the table. These are prompts
the students can use to try to build the links in their chain. For example, say, “which link
would you like to try first, maybe snap your wrist?” The students would then test their
chain and toss the ball into the air by snapping their wrist. The student records this motion
as the first step in their chain. Continue the exploration by asking, “How can you add more
force? Which link could you add to your chain to make the ball go higher?” Have students
continue to analyze how high they are throwing the ball, how well their kinetic chain is
working. Encourage students to think about what they should add or revise in their list of
links to make a more effective kinetic chain, to make the ball fly higher. Extend the lesson: Once students have demonstrated a basic understanding of what a
kinetic chain is and how it relates to the motion of a body, ask students to work with a
partner to build a kinetic chain that uses force and motion to create a better tennis serve.
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snap your wrist
bend your elbow
pull your arm back
jump in the air
bend at the knees
crouch down to the floor
arms at your side
reach above your head
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You have the potential to transfer energy
Materials
Two yardsticks, several different kinds of balls: tennis balls, marbles,
plastic balls, and a copy of the chart for recording results
Set Up
Line up two yardsticks side by side on a smooth table top. Place different
types of balls on the table next to the yardsticks. There should be several
balls of each type to allow for experimentation. Print out a copy of the chart,
provided below, to use for recording results (the first example has been
filled in for reference).
To Play
Invite students to stand around the table and look at the yardsticks and balls.
Ask students, “Do you see anything moving? Do they see any work being done
or any signs of energy?” Even if you can’t see it, the balls are filled with energy,
but when a ball doesn’t move, the energy is stored. We call this potential
energy. Ask, “How do we get the stored potential energy out of the ball?” Let’s explore! Have students choose the type of balls they want to use to
problem solve. Ask them to use the yardsticks to create a track. Place three
balls, of the same size and weight, in the center of the track. The balls should
be touching one another. Then, place another ball, of the same size, at the
end of the track.
Say, “The balls aren’t moving, they are still storing energy, potential energy.
How do we get these balls moving? How can we get the balls moving using
only one other ball? Let’s put one ball to work and move it so it hits the
other three balls.” Ask a volunteer to roll the ball at the end of the track so
that it hits the other balls. Before a student pushes the ball, ask him to predict
how many balls they think will move when the force of the single ball hits
the three balls. The ball will roll down the track, hit the three balls and one
ball will move.
What just happened? Tell us one thing you noticed. Ask, “The balls moved,
does that mean the stored energy was released? Who predicted this would
be the result? Did anyone have a different prediction?” When a ball doesn’t
move it is called potential energy? However, a moving ball can do work. STEM in Sports is brought to you by Time Warner Cable’s Connect a Million Minds
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You have the potential to transfer energy
Another word for work is energy. When objects move, they release stored
energy, called kinetic energy, the energy of moving objects. We just saw how potential energy can be transferred into the kinetic energy of
a rolling marble. Can we draw any conclusions about how much energy we just
saw transferred? One ball hit three balls and one ball moved. A rolling marble
can only transfer the energy it has stored. Lets record this on our chart and try
the same experiment rolling two balls at three balls. Predict what will happen
and record the results. Encourage students to try different variations of balls,
different sizes, always asking them to predict and record the results. Extend the lesson: Where can potential and kinetic energy be found on a
tennis court? Walk students through various types of shots. Have them think
about how their bodies, the racket and the ball are storing potential energy
and how motion converts and transfers potential to kinetic energy.
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Experiment 8
Experiment 7
Experiment 6
Experiment 5
Experiment 4
Experiment 3
Experiment 2
Experiment 1
# of balls that
roll
1
size of ball(s)
providing force
small
small
3
Size of ball(s)
receiving energy # of balls in row
1
# of balls that
move
Conclusion
the rolling marble can
only transfer the amount
of potential energy it has
stored, 1:1
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