CECsci.136


TITLE:    TIMS (TEACHING INTEGRATED MATH AND
          SCIENCE)  THE BOUNCING BALL
          COPYRIGHT TIMS, M/C 249, UIC, BOX 4348,
          CHICAGO IL  60680

AUTHOR:   Bonnie Custer, St. Agatha School,
          Portland, Oregon

GRADE LEVEL/SUBJECT:
This activity can be adapted to many grade levels.
Primary students can collect and record data using
simple data tables.  The teacher can do the graphing as
a class activity.  The comprehension questions can be
geared for lower grades.

Upper grade and middle school students can transfer and
compare the bounce heights of different types of balls.
It can be as simple or challenging as the teacher
chooses to make it.

OVERVIEW:
This is an adaptation of one of the TIMS experiments I
use  with my students.  For more complete information
write to TIMS at the above address.

This is one of the first experiments where students use
two quantitative variables.  In this experiment they
determine the exact relationship between the height
from which a ball is dropped and the distance that it
rebounds.

The joy of TIMS experiments is that students become
mini-scientists.  They collect data, graph data, and
through specific questions analyze the data.

PURPOSE:  The Bouncing Ball familiarizes students with
science vocabulary (ie. variables, manipulated
variables, responding variables, fixed variables) in a
concrete and practical way.  They conduct this
experiment using the same steps as researchers today
conduct experiments for cures for cancer, models of the
universe.  The only different is the number and
complexity of the variables.  The students look for a
direct relationship between variables.  The older
students  use proportional reasoning to mathematically
explore direct relationships.

OBJECTIVE(s):
1.  Identify manipulative and responding variables.
2.  Identify fixed variables.
3.  Experiment to find bounce heights for drop
    heights of 40 cm, 80 cm, and 120 cm.
4.  Record data.
5.  Use graphs to analyze data.
6.  Use graph to predict drop heights and bounce
    heights.

RESOURCES/MATERIALS:
EACH TEAM OF 2 STUDENTS WILL REQUIRE:
1 METER STICK AND A CENTIMETER RULER
1 TENNIS BALL
1 SUPER BALL (FOR UPPER AND MIDDLE GRADES)
MASKING TAPE

ACTIVITIES AND PROCEDURES:
The TIMS steps:   (These steps are used in all TIMS
experiments)

After the teacher explains and models the above steps
the students:
1.   Draw a detailed picture of the experiment.
     (Procedure)  This helps the teacher check for
     understanding. The picture includes the materials,
     the actions of the students, and the labeled
     variables (D) and (B)
2.   The students experiment and record data on a
     teacher-made data table.
3     The students graph their results.  The
     manipulated variable (D) on the horizontal axis,
     and the responding variable (B) on the vertical
     axis.
4.   Comprehension questions.


THE EXPERIMENT
1.   The students work in teams of two, one to drop the
     ball, one to see how high it bounces.
2.   Tape a meter stick to the wall in vertical
     position with one end touching the floor.  Be sure
     small numbers are by the floor.
3.   Have one team member hold the tennis ball so that
     the bottom of the ball is 40 cm from the floor.
     (D)
4.   Have the children make several practice trial runs
     in order to observe the approximate bounce height.
     Make sure they drop the ball not throw it.
5.   The partner reads the measurement of the bounce
     height (B).  The child will have to kneel or lie
     on the floor to do this accurately.
6.   The children should record the measurement (B)
     under trial 1 of the data table.  Have the
     students repeat for trial 2 and trial 3.
     The partners should trade places for each trial.
7.   Tell the children that the trials should be within
     a few cm of each other and to raise their hands
     for help if they are too far apart.
8.   After 3 trials have been recorded the should
     calculate the average.  For younger students who
     can't calculate averages use an "Eyeball" average.
     Pick the one in the middle.  For example:  30 cm,
     29 cm, 32cm.  30 is the middle one so 30 is the
     "Eyeball" average.
9.   Have children repeat the procedure for 80 cm and
     again for 120 cm.
10.  For Upper and Middle grade students repeat all of
     the steps above using a super ball instead of the
     tennis ball.

THE COMPREHENSION QUESTIONS
1.   What is the manipulated variable?
     (D - Drop height)
2.   What is the responding variable?
     (B - Bounce height)
3.   What variables are held fixed during the
     experiment?
     (Type of ball, floor, the way the ball is
     released)
4.   Why is it a good idea to carry out three trials?
     (To check of big mistakes, to be more accurate)
5.   Why do you take an average for the numerical value
     B?
     (To find the best value)

Use your graph to answer these questions?
6.   If the drop height of the tennis ball is 60 cm,
     what is the bounce height?
7.   If the ball rebounds to a height of 55 cm, from
     what height was it dropped?

CONCLUSION:  The students should recognize the direct
relationship between drop height and bounce height.
They may want to design their own experiments using
other balls and compare results.