AskERIC Lesson Plans
Lesson Plan #: AELP-GEN0020


Slippery Substances - Lubricants

An AskERIC Lesson Plan


Submitted by:Rebecca Sexson, Anasazi Elementary School, Scottsdale, AZ
Endorsed by: These lesson plans are the result of the work of the teachers who have attended the Columbia Education Center's Summer Workshop. CEC is a consortium of teacher from 14 western states dedicated to improving the quality of education in the rural, western, United States, and particularly the quality of math and science Education. CEC uses Big Sky Telegraph as the hub of their telecommunications network that allows the participating teachers to stay in contact with their trainers and peers that they have met at the Workshops.
Date: May 1994


Grade Level: Appropriate for grades 3-4.

OVERVIEW:  Slippery Substances are called lubricants.
They are very important in modern technology.  Cars,
trucks, airplanes, and machines all have parts that rub
against one another.  These parts would heat up, wear
down, and stop working if we did not have lubricants.
Lubricants reduce the amount of friction between 2
surfaces that move against each other.

OBJECTIVE(s):  Students will be able to:
1.  Demonstrate which lubricant is best
    (slipperiest), of those used for the experiment.
2.  Explain how a lubricant works.
3.  Identify objects that need lubricants to work
    well.

RESOURCES/MATERIALS:
Teacher Materials = 4 envelopes unflavored gelatin, 8
inch square baking pan, mixing bowl, liquid dish
detergent, vegetable oil, 2 bowls, clock or watch with
a second hand, a knife, measuring cup

Student Materials = pencil, science journals

ACTIVITIES AND PROCEDURES:
1.   Dissolve 4 envelopes of gelatin in a bowl of 2
     cups of hot tap water.
2.   Coat the inside of a 9 x 12 inch pan with
     vegetable oil.  Pour the gelatin mixture into the
     pan and refrigerate until firm (about 3 to 4
     hours).
3.   Cut the gelatin into cubes about 1x1x1 inch, with
     a knife.  You should have about 64 cubes.
4.   Place 15 cubes into a bowl.  Place the second bowl
     about 6 inches away from the cube bowl.
5.   See how many cubes can be transferred to the other
     bowl in 15 seconds by using your thumb and index
     finger one at a time. (Don't squeeze!)

     CAUTION:  Children should be cautioned not to eat
     the gelatin cubes after they have been handled or
     after they are covered with lubricant.

6.   Return all the cubes to the first bow.  Pour 1/4
     cup dish detergent over the cubes.  Gently mix the
     detergent and the cubes so that the cubes are
     well-coated.
7.   Use the same method as before to transfer as many
     cubes as possible in 15 seconds.
8.   Throw away the cubes and detergent and wash and
     dry both bowls.  Put about 15 new cubes into one
     bowl and; pour 1/4 cup water over the cubes, again
     making sure the cubes are thoroughly coated.  See
     how many cubes you can transfer in 15 seconds.
9.   Throw away the cubes and water.  Put about 15 new
     cubes into one bowl.  Pour 1/4 cup of vegetable
     oil over the cubes.  Make sure they are well
     coated.  See how many cubes you can transfer in 15
     seconds.
10.  Analyze your findings.  With which liquid were you
     able to transfer the most cubes?  With which
     liquid were you able to transfer the fewest cubes?
     Which was the best lubricant (the slipperiest)?
     Which was the worst?


TYING IT ALL TOGETHER:  Students should now understand
vocabulary words such as lubricant, friction, gravity,
force, momentum, and machine.  This is an ideal
activity to follow a study of simple machines.  Mr.
Gumpy's Motorcar, written by John Burningham, is a good
introduction and motivator.  Students should be able to
list objects that have working parts that would need
lubricants to protect their parts, such as cars,
trucks, bicycles, etc.

This activity has been copied, with permission, from the Educational Resources Information Center (ERIC) server to ours, to allow faster access from our website. We encourage you to explore the original site.

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