Bounce Back Ball Experiment
(Teacher version)
NGSSS Science Benchmarks:
SC.4.N.1.6, SC.4.P.10.1, SC.4.P.10.2, SC.5.N.1.1, SC.5.P.10.2, SC.5.P.13.1
NGSSS Mathematics Benchmarks:
MACC.5.MD.2: Represent and interpret data.
MACC.5.G.1: Graph points on the coordinate plane to solve real-world and
mathematical problems.
Description:
Students will be working in teams of four to measure the rebound heights of a tennis
ball dropped from four different heights. Students will also be investigating with the
bouncing balls to measure changes in the type of energy they possess.
Performance Expectations:
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Developing a hypothesis
Identifying test variable (independent/manipulated), outcome variable
(dependent/responding), and constant variables
collecting data on the rebound heights of a tennis ball
using a meter stick to measure the heights of ball bounces
representing data in the table and graph
using addition and division to determine the mean
General Instructions to the Teacher:
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This task is designed to take students approximately 1 class period to complete
Students will be working in groups during this exercise.
Students should be ready to work as soon as the period begins. The materials
should be set out at each lab station, if possible. A central supply area, if
needed, should be easily accessible.
Model to students how the release and rebound height of the bouncing ball is
done.
Materials for "Bounce Back Ball" experiment:
At each station students should have:
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1 tennis ball
1 meter stick
Lab guides and science journal for recording data
masking tape (enough to hold the meter stick to the wall)
4 calculators (for individual calculations or 1 calculator per group)
Advance Preparation:
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Prior to testing, familiarize yourself with the teacher demonstration.
Tape a meter stick to the wall so 0 cm is on the floor and 100 cm is at the top. Be
sure that the students will be able to see the stick when they are viewing the
demonstration as a group.
Write the following definitions on the chalkboard:
Energy-the ability to do work
Mechanical Energy can be classified as;
o Energy of position: Is the energy that is stored in an object by its position
or chemical composition
o Energy of Motion: Is the energy of matter in motion
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Plan to assign students to groups of four. Assign each student a number from
1-4. If you do not have four students in a group, students may double up on
assignment.
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Write the following student assignments on the chalkboard:
o Student One will be the taper: Your job is to tape the meter stick to the
wall or any stable vertical surface
o Student Two will be the dropper: Your job is to drop the ball
o Student Three will be the spotter: Your job is to sit on the floor and take
the measurement carefully, looking straight at the meter stick
o Student Four will be the recorder: Your job is to record the measurements
.
References:
Modified and adapted from CPALMS and Discovery resources
http://www.cpalms.org/RESOURCES/URLresourcebar.aspx?ResourceID=wyXINsSsSf8=D
http://pals.sri.com/tasks/5-8/BounceBall/directs.html
Discovery Resource: How Scientists work series: What is the Scientific Method: Ball
Bounce
Bounce Back Ball Experiment
(Student version)
Group Members: _______________________________________________________
________________________________________________________
________________________________________________________
Description:
You will be working in teams of four to measure the rebound heights of a tennis ball
dropped from four different heights. You will be investigating with the bouncing balls to
measure changes in the type of energy they possess.
Materials per group:
 1 tennis ball
 1 meter stick
 Science journal and lab sheet for recording data
 masking tape (enough to hold the meter stick to the wall)
 4 calculators or 1 calculator per group
Directions:
Each team member will have a job to do based on a number: 1, 2, 3, or 4.
Number 1: Tape the meter stick to the wall or any stable vertical surface with 0 cm at
the bottom.
Number 2: Drop the tennis ball from each of the different heights three times as shown
on the chart.
Number 3: Take the measurement of the rebound. Be sure to use the bottom edge of
the ball for your measurements. You should sit on the floor directly in front of the meter
stick and be ready to watch the ball bounce.
Number 4: Record the data. Make sure other team members copy the data into their
Science Journal after all data is collected.
Problem Statement:
Does the height that a rubber ball is dropped from affect its bounce height?
Hypothesis:
Make a prediction as to what you think will happen to the height of a bounce if a rubberball is dropped from different heights.
Example: If the ball is dropped from _____ cm, then the bounce height will be ____cm.
Variables: What would be your test variable (independent/manipulated)?
What would be your outcome variable (dependent/responding)?
Constant variables: _____________________________________________
Activity:
1.
Conduct the trials and have the recorder complete the "Ball Rebound Heights"
chart. When you have completed all of the trials, each of you should copy the
data onto your own charts.
Ball Rebound Heights
Starting
Height
Trial 1
Trial 2
Trial 3
Average
100 cm
80 cm
60 cm
40 cm
2.
Suppose that one of your classmates had stated that a ball will not bounce back
to the starting height no matter what the starting position might be. Using
evidence from you investigation, explain whether or not you think your
classmate's statement was true.
_____________________________________________________________
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3.
Construct a graph that illustrates the mean rebound height for each drop height
as calculated in Step 1. Use DRY MIX criteria for graphing (DRY, D=dependent
variable, or R= responding variable should go on the Y axis.
MIX (M= manipulated variable or I = independent variable goes on X-axis)
Y
X
4.
In this investigation, you measured the starting height and the rebound height of
the ball. Now let's look at the type of energy the ball had at different times.
.
STEP 1: Identify the kind of energy the ball had when you held the ball at
100 cm.? ______________________________________________
STEP 2: Explain your answer.
_________________________________________________________
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_________________________________________________________
STEP 3: Identify the kind of energy when the ball was released.
Explain your answer
__________________________________________________________
__________________________________________________________
5.
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Suppose the rebound height of a ball was 80 cm when its starting height was 100
cm. Explain what caused the difference in the amount of energy in the ball.
________________________________________________________________
________________________________________________________________
Conclusion: Answer the following questions:
1. What was investigated? (State the purpose of the experiment by describing the
problem statement.)
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2. Was your hypothesis supported by the data? (Write a statement as to whether
the data supports or does not support the hypothesis including a restatement of the
hypothesis.)
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3. What were the major findings? (Describe the data collected that provides the
evidence as to why the hypothesis was supported or not supported.)
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4. What possible explanations can you offer for your findings? (Think about
everything that may have affected your results.)
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Application: Answer the following questions:
1. How can the investigation be improved?
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2. What are some possible applications of the experiment? (Describe how the
findings from this investigation can be used in day-to-day life.)
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3. What questions has your experiment lead you to ask that could be tested in a
new an investigation.
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Enrichment / Extension Activity:
A researcher conducted a similar experiment using rubber-ball and was able to develop
a mathematical equation from his results. He found that Y = 3/4 X, where X represents
the dropped heights and Y represents the bounce heights. Since 3/4 is equal to 75%,
then one can conclude that the bounce height is about 75% of the dropped height. From
the class data you collected in this experiment, could you develop a mathematical
equation?