UC Irvine FOCUS!
5 E Lesson Plan
Title: Bouncing Balls
Grade Level and Course: 8th Grade and high school Physics
Materials:
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borax (found in the laundry section of the store)
cornstarch (found in the baking section of the store)
white glue (e.g., Elmer's glue - makes an opaque ball) or blue or clear school glue (makes a
translucent ball)
warm water
food coloring (optional)
measuring spoons
spoon or craft stick to stir the mixture
2 small plastic cups or other containers for mixing
marking pen
stopwatch
metric ruler
zip-lock plastic baggie
Instructional Resources Used: (concept maps, websites, think-pair-share, video clips, random
selection of students etc.)
 websites
 small group work
 data and observation worksheets
California State Standards: (written out)
th
8 Grade:
Motion
1. The velocity of an object is the rate of change of its position. As a basis for understanding this concept: a. Students
know position is defined in relation to some choice of a standard reference point and a set of reference directions.
b. Students know that average speed is the total distance traveled divided by the total time elapsed and that the
speed of an object along the path traveled can vary. c. Students know how to solve problems involving distance, time,
and average speed. d. Students know the velocity of an object must be described by specifying both the direction and
the speed of the object. e. Students know changes in velocity may be due to changes in speed, direction, or both. f.
Students know how to interpret graphs of position versus time and graphs of speed versus time for motion in a single
direction.
Forces
2. Unbalanced forces cause changes in velocity. As a basis for understanding this concept: a. Students know a force
has both direction and magnitude. b. Students know when an object is subject to two or more forces at once, the
result is the cumulative effect of all the forces. c. Students know when the forces on an object are balanced, the
motion of the object does not change. d. Students know how to identify separately the two or more forces that are
acting on a single static object, including gravity, elastic forces due to tension or compression in matter, and friction.
f. Students know the greater the mass of an object, the more force is needed to achieve the same rate of change in
motion.
Reactions
5. Chemical reactions are processes in which atoms are rearranged into different combinations of molecules. As a
basis for understanding this concept: a. Students know reactant atoms and molecules interact to form products with
different chemical properties. b. Students know the idea of atoms explains the conservation of matter: In chemical
reactions the number of atoms stays the same no matter how they are arranged, so their total mass stays the same.
c. Students know chemical reactions usually liberate heat or absorb heat.
High School:
Motion and Forces
1. Newton’s laws predict the motion of most objects. As a basis for understanding this concept: b. Students know that
when forces are balanced, no acceleration occurs; thus an object continues to move at a constant speed or stays at
rest (Newton’s first law). c. Students know how to apply the law F=ma to solve one-dimensional motion problems that
involve constant forces (Newton’s second law). d. Students know that when one object exerts a force on a second
object, the second object always exerts a force of equal magnitude and in the opposite direction (Newton’s third law).
e. Students know the relationship between the universal law of gravitation and the effect of gravity on an object at
the surface of Earth. i.* Students know how to solve two-dimensional trajectory problems. j.* Students know how to
resolve two-dimensional vectors into their components and calculate the magnitude and direction of a vector from its
components.
Conservation of Energy and Momentum
2. The laws of conservation of energy and momentum provide a way to predict and describe the movement of
objects. As a basis for understanding this concept: b. Students know how to calculate changes in gravitational
potential energy near Earth by using the formula (change in potential energy) =mgh (h is the change in the elevation).
c. Students know how to solve problems involving conservation of energy in simple systems, such as falling objects. f.
Students know an unbalanced force on an object produces a change in its momentum. g. Students know how to solve
problems involving elastic and inelastic collisions in one dimension by using the principles of conservation of
momentum and energy. h.* Students know how to solve problems involving conservation of energy in simple systems
with various sources of potential energy, such as capacitors and springs.
Chemical Bonds
2. Biological, chemical, and physical properties of matter result from the ability of atoms to form bonds from
electrostatic forces between electrons and protons and between atoms and molecules. As a basis for understanding
this concept: a. Students know atoms combine to form molecules by sharing electrons to form covalent or metallic
bonds or by exchanging electrons to form ionic bonds. d. Students know the atoms and molecules in liquids move in a
random pattern relative to one another because the intermolecular forces are too weak to hold the atoms or
molecules in a solid form. e. Students know how to draw Lewis dot structures. f.* Students know how to predict the
shape of simple molecules and their polarity from Lewis dot structures. h.* Students know how to identify solids and
liquids held together by van der Waals orces or hydrogen bonding and relate these forces to volatility and boiling/
melting point temperatures.
Conservation of Matter and Stoichiometry
3. The conservation of atoms in chemical reactions leads to the principle of conservation of matter and the ability to
calculate the mass of products and reactants. As a basis for understanding this concept: a. Students know how to
describe chemical reactions by writing balanced equations. e. Students know how to calculate the masses of reactants
and products in a chemical reaction from the mass of one of the reactants or products and the relevant atomic
masses. f.* Students know how to calculate percent yield in a chemical reaction.
Common Core State Standards: (written out)
Writing Standards:
Grade 8: 1. Write arguments to support claims with clear reasons and relevant evidence. a. Introduce claim(s),
acknowledge and distinguish the claim(s) from alternate or opposing claims, and organize the reasons and evidence
logically. b. Support claim(s) with logical reasoning and relevant evidence, using accurate, credible sources and
demonstrating an understanding of the topic or text. c. Use words, phrases, and clauses to create cohesion and clarify
the relationships among claim(s), counterclaims, reasons, and evidence. d. Establish and maintain a formal style. e.
Provide a concluding statement or section that follows from and supports the argument presented. 4. Produce clear
and coherent writing in which the development, organization, and style are appropriate to task, purpose, and
audience. 8. Gather relevant information from multiple print and digital sources, using search terms effectively;
assess the credibility and accuracy of each source; and quote or paraphrase the data and conclusions of others while
avoiding plagiarism and following a standard format for citation.
Grades 11-12: 1. Write arguments to support claims in an analysis of substantive topics or texts, using valid reasoning
and relevant and sufficient evidence. a. Introduce precise, knowledgeable claim(s), establish the significance of the
claim(s), distinguish the claim(s) from alternate or opposing claims, and create an organization that logically
sequences claim(s), counterclaims, reasons, and evidence. c. Use specific rhetorical devices to support assertions
(e.g., appeal to logic through reasoning; appeal to emotion or ethical belief; relate a personal anecdote, case study,
or analogy). f. Provide a concluding statement or section that follows from and supports the argument presented. 2.
Write informative/explanatory texts to examine and convey complex ideas, concepts, and information clearly and
accurately through the effective selection, organization, and analysis of content. b. Develop the topic thoroughly by
selecting the most significant and relevant facts, extended definitions, concrete details, quotations, or other
information and examples appropriate to the audience’s knowledge of the topic. e. Establish and maintain a formal
style and objective tone while attending to the norms and conventions of the discipline in which they are writing.
Lesson Objectives: Students will make bouncing balls by mixing white glue, water, borax, and
cornstarch. [Chemical reaction; polymers] Students will then experiment with variations on the
formula to create a ball that bounces as high as possible when dropped from a fixed distance.
Variations may include ratio of mixtures, size/mass of ball, etc. Students may further investigate
the uniqueness of polymers and what does or does not constitute a polymer.
Differentiation Strategies to meet the needs of diverse learners:
 English Learners: relate the activity to writing in a purposeful manner and connect to
personally meaningful experiences; utilize peer interaction and discussion
 Special Education: non-threatening hands-on activity; peer interaction and discussion;
teacher has more time and opportunities to meet individual student needs; gives all
students the chance to show their strengths and feel included in the classroom
 GATE: students will be invited to participate in an experiment in which they will be
challenged to find the best solution. This project will have many possible solutions, and
students will be expected to go beyond the minimum expectations to complete it. If
polymers are not specifically addressed, students may be challenged to do the research
and present findings.
ENGAGE
 Describe how the teacher will capture the students’ interest.
 What kind of questions should the students ask themselves after the engagement?
The reaction of the borax mix and glue mix is dramatic and instant. Having students use the
“control” formula the students will have an opportunity to witness the reaction and play with the
resulting “goo” forming it into a ball and making initial observations.
Students should question what makes the ball bounce and what elements of the formula
might be changed to improve the performance.
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What kind of questions should the students ask themselves after the engagement
(missing)?
EXPLORE
 Describe the hands-on laboratory activity that the students will be doing.
 List the “big idea” conceptual questions that the teacher will ask to focus the student
exploration.
Students will make bouncing balls from some simple ingredients. Students will conduct an
experiment with variations of the formula to make a ball that bounces higher (when dropped
from a prescribed height) than the original control formula.
[Note: Experiments can be done with the ratio between the amounts of glue, cornstarch, and
borax. Adding more cornstarch will make a ball that stretches and bends. Using less borax will
produce a 'goopier' type of ball. Add more glue for a slimier ball. This information may or may
not be shared with students dependent upon whether the teacher would like the students to
make these discoveries or work with these given facts in setting up their experiments.]
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List the “big idea” conceptual questions that the teacher will ask to focus the student
exploration.
EXPLAIN
 What is the “big idea” concept that students should have internalized from doing the
exploration?
 List the higher order questions that the teacher will ask to solicit student explanations
for their laboratory outcomes, and justify their explanations.
Big idea:
 Students will find that the mass of the ball may have as much of an effect on its performance
as the chemical make-up. Students will find that through precise recording of formulas and
measurements that they will be able to prove that results can vary significantly.
Questions:
 Analysis: Explain what happened when the formula was changed. Distinguish between a
change in formula and a change in mass.
 Synthesis: Predict what would happen if the formula was changed vs. the mass (or visa versa
based on what the experiment called for)? Propose further changes to the formula or mass
that would yield better results.
 Evaluation: Justify the reasoning for the formula/mass changes made in the experiment.
Convince others of the best combination of formula and mass changes to produce the “best”
bouncing ball.
EXTEND
 Explain how students will develop a more sophisticated understanding of the concept.
 How is this knowledge applied in our daily lives?
Students will have the opportunity to observe a control model, then propose and test a single
variable to produce better results when dropping the ball from a fixed distance. Successes and
failures will be documented and explained. Principles of motion and forces will be examined as
well as proper procedures in investigation and experimentation.
Connections to daily life are made in finding the value in attention to detail in collecting data
and making observations. Students will also gain a better understanding of chemical reactions
and what can happen when elements and compounds are combined.
EVALUATE
 How will the student demonstrate their new understanding and/or skill?
 What is the learning product for the lesson?
Understanding and/or skill will be demonstrated in an experiment that is well-documented
and supported. Evaluation of the results—whether the given hypothesis was correct or not—
should indicate an understanding of the chemistry applied as well as the laws of physics (such as
the relationship of mass to velocity).
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What is the learning product for the lesson?
Background Knowledge for the Teacher:
“Students in grade eight study topics in physical sciences, such as motion, forces, and the
structure of matter, by using a quantitative, mathematically based approach similar to
the procedures they will use in high school. Earth, the solar system, chemical reactions,
the chemistry of biological processes, the periodic table, and density and buoyancy are
additional topics that will be treated with increased mathematical rigor, again in
anticipation of high school courses. Students should begin to grasp four concepts that
help to unify physical sciences: force and energy; the laws of conservation; atoms,
molecules, and the atomic theory; and kinetic theory. Those concepts serve as important
organizers that will be required as students continue to learn science. Although much of
the science called for in the standards is considered “classical” physics and chemistry, it
should provide a powerful basis for understanding modern science and serve students as
well as adults.
Mastery of the eighth-grade physical sciences content will greatly enhance the ability of
students to succeed in high school science classes. Modern molecular biology and earth
sciences, as well as chemistry and physics, require that students have a good
understanding of the basics of physical sciences.”
“Experiments can yield consistent, reproducible answers, but the answers may be
incorrect or off the mark for many reasons. By the time students complete grade eight,
they should have a foundation in experimental design and be able to apply logical
thinking processes to evaluate experimental results and conclusions. Mathematical
representation of data is the key to making quantitative scientific predictions. Graphs
expressing linear relationships utilize proportional reasoning and algebra. Students
should be taught to apply their knowledge of proportions and algebra to the reporting
and analysis of data from experiments.”
Science Framework for California Public Schools: Kindergarten Through Grade Twelve
Bouncing Balls
Challenge
Design a better bouncing ball.
Criteria
Don’t Wants
 ABS
 Too much goo
 No bounce
 Not measurable
Needs
 NBS
 3d
 Use given formula as the control
 Make a change to the formula OR change
the mass of the ball to yield better results
(more bounce)
 Conduct an experiment
Procedure for Control
1. Label one cup 'Borax Solution' and the other cup 'Ball Mixture'.
2. Pour 2 tablespoons warm water and 1/2 teaspoon borax powder into the cup labeled
'Borax Solution'. Stir the mixture to dissolve the borax. Add food coloring, if desired.
3. Pour 1 tablespoon of glue into the cup labeled 'Ball Mixture'. Add 1/2 teaspoon of the
borax solution you just made and 1 tablespoon of cornstarch. Do not stir. Allow the
ingredients to interact on their own for 10-15 seconds and then stir them together to
fully mix. Once the mixture becomes impossible to stir, take it out of the cup and start
molding the ball with your hands.
4. The ball will start out sticky and messy, but will solidify as you knead it.
5. Once the ball is less sticky, go ahead and bounce it!
6. You can store your plastic ball in a sealed ziploc bag when you are finished playing with
it.
7. Don't eat the materials used to make the ball or the ball itself. Wash your work area,
utensils, and hands when you have completed this activity.
Step 1: Observations
1. During the mixing:
a. Describe the Borax solution:
b. Describe the Ball Mixture:
2. After the mixing:
a. How did the mixture change over a period of time? (A few minutes to several
minutes):
b. What part of the ingredients had the greatest effect on the bounciness? Will
variations in the formula yield better results or will change in mass have a
greater effect? Why?
3. When dropped from a height of 3 meters, how high did the control bounce? Were
results relatively consistent with other groups’ results?
Step 2: Hypothesis
Now the procedures can be varied and observations used to make predictions about the effects
of the changes.
 Observations may lead to a change in the composition of the ball including the diameter of
the finished ball, how sticky it is, how long it takes to solidify into a ball, and how high it
bounces.
 Some possible variables may be to work with the ratio between the amounts of glue,
cornstarch, and borax, adding more or less cornstarch, or using more or less borax.
Hypothesis [written as an “If…then…” statement]:
Step 3: Design the Experiment
Describe the (detailed) steps in conducting the experiment. Procedures for making the Control
can be copied from above and copied again for the variable—making sure to note the one
change to be tested. Note: an experiment is invalid if it cannot be duplicated—detailed
procedures are critical.
Step 4: Test the Hypothesis
Test #
Bounce Height
Control
Observations
Test #
Bounce Height
Variable
Observations
Height of Bounce
Graph of Results
Test 1
Test 2
Analysis of quantitative results:
Analysis of qualitative results:
Test 3
Test 4
Test 5
Step 5: Accept or Reject the Hypothesis
1. Was the hypothesis correct, incorrect, or inconclusive?
2. What specific results led to the conclusion?
Note: Accepting a hypothesis does not guarantee that it is the correct hypothesis! This only means that the
results of your experiment support the hypothesis. It is still possible to duplicate the experiment and get
different results next time. It is also possible to have a hypothesis that explains the observations, yet is the
incorrect explanation. Remember, a hypothesis can be disproven, but never proven! If the hypothesis was
rejected, it may be appropriate to return to step 2 and reconsider given the additional data.
This activity is adapted from the American Chemical Society's "Meg A. Mole's Bouncing Ball", a featured project for
National Chemistry Week 2005.