### Academy Curricular Exchange Columbia Education Center  Science

TITLE:    DOWNHILL DISCOVERIES

AUTHOR:   Marty Stallings, Orvis Risner Elementary
School, Edmond, OK

Science and Math.

OVERVIEW:  The popularity of the recent Winter Olympics
afforded an excellent opportunity to relate certain
competitive events to the teaching of such physical
properties as potential and kinetic energy, friction,
drag, and acceleration.  Through student made sloping
tracks and selected course variables, students were
involved in hands-on activities to determine how course
conditions affect bobsled, luge, and downhill ski
races.

PURPOSE:  To help students understand physical
properties such as kinetic and potential energy,
friction, drag, slope, and acceleration .  It is also
important to be able to relate these properties to
everyday experiences.

OBJECTIVES:  Students will be able to:
1.  Explain the difference between potential and
kinetic energy.
2.  Demonstrate, using graphical analysis, how
different variables affect the same mass.
3.  Demonstrate, using graphical analysis, how slope
angle affects distance the same mass travels.
4.  Identify considerations that are made to
determine optimum downhill racing conditions.
5.  Relate basic physical properties to everyday
situations.
6.  Identify that learning is relevant.

RESOURCES/MATERIALS:  Cardboard, tape, small fan,
water, salt, cornstarch, butter, centimeter tape
measure, a carpenter's square (this is large enough to
measure slope angle easily), aluminum foil, waxed
paper, clay, checkers, pencil, and graph paper.

ACTIVITIES AND PROCEDURES:
l.   Cut five strips of aluminum foil or waxed paper 30
centimeters (about l2 inches) long and 6
2.   Tape them on the top to a piece of rigid cardboard
(one long side of an appliance (refrigerator) box
works well).  Be sure to smooth out foil or paper
as you tape at the top.  (Don't tape the bottom of
the strip as this will alter your results.)
3.   On strip l, sprinkle salt and water; strip 2, put
on cornstarch;  strip 3, water only.  Spread a
thin coat of butter on strip 4.  Have a fan ready
to blow on strip 5.
4.   Prop the cardboard up at a 45 degree angle.
5.   Review the idea that potential energy is stored
energy(the sled or skier at the top) and kinetic
energy is energy of mass and motion (the sled or
skier going downhill).  Talk about the forces that
slow a sled or skier down--drag against the air
and friction against the ground.
6.   Divide the class into 5 teams.  Have someone from
each team hold a checker at the top of a different
strip.  At your command, they all let go of their
checker.
7.   Each team is to measure in centimeters and record
the distance their checker traveled.
8.   Have each team rotate strips until they have
completed all 5 strips.
9.   Teams will then record their results on graph
paper using a bar graph.
10.  Allow each team to make their own tracks and
strips to allow experimentation  with different
angles of slope, more or less substance on strips
and possible weight increases using clay.
11.  Record on graph paper results using different
variables designed by the 5 teams.

TYING IT ALL TOGETHER:  Have each team share results of
their variables and track designs with the total group.
Upon completion of group activities, children should
summarize results using physical variables such as
friction, acceleration, and mass in relation to
distance and speed traveled.   The children will then
be able to apply knowledge learned to considerations
the Olympic Committee must make in the selection of
appropriate slopes as well as the aerodynamics of the
bobsled, luge, and skiers themselves.