Mathematics/Physics

The Great Tin Race

 Bernina L. Norton Abbott School 3927 W. Fillmore St. 3630 S. Wells St. CHICAGO IL 60624-4206 CHICAGO IL 60609 (773) 419-0516 (773) 535-1660

Objective(s):

Upon completion of this lesson, 6th-8th grade students will be able to:

Describe and recognize motion

Understand what is a reference point

Describe distance in reference to units of measurement

Calculate speed

Calculate average speed

## Measure distance

Understand the relationship between distance and time (speed= distance/ time)

Graph data

Use data to make hypotheses

Materials:

·       Various sizes of tin cans with the tops and bottoms removed (open ends)

·       Two plastic lids per tin can

·       Rubber bands

·       Paper clips

·       Pencils

·       Meter sticks

·       Measuring tape (inches)

·       Masking tape

·       Calculators (optional)

·       Timers

Strategy:

The strategies devised to carry out my objectives are as follows:

·       Lead inquiry discussion about motion concepts

o      Defining motion

o      Recognizing motion

o      Reference point

o      Describing distance

o      Calculating speed

o      Average speed

·       Distribute tin racer blueprint sheets, racer data sheets, and speed graphs. (Enlarge one of the speed graphs to record the groups’ average speed at 2 m)

·       Allow students time to construct tin racers, raceway and complete racer data sheets.

Note:   To complete racer data sheets, the following information is needed:

o      Distance, time, and speed for three trials

o      Average speed

·       Have each group place on the chart the data of their racer (distance vs. time).

·       Ask students to make predictions based on the group data, i.e. which racer will be the fastest.

·       Conduct the tin race (construct a raceway at 3 meters). Record the fastest racers/speed.

·       Compare the predictions with the actual results.

·       Discuss ways to improve the speed of the racers.

·       If time allows, test those improvements, calculate the speed, and record.

Performance Assessment:

Were the students able to follow the blue prints to construct the racers?

Were the students able to measure the distance and time of the racers?

Were the students able to calculate the speed of the racers for each trial?

Were the students able to calculate the average speed at 1 m? At 2 m?

Were the students able to construct motion graphs of their racer’s speed?

Were the students able to make predictions based on the group data?

Were the students able to think of ways to improve their racers?

Conclusions:

Through this exercise, students are able to follow directions to construct both the racers and the raceway.  Students use measurement skills to conduct the raceway.  Timers allow students to approximate the time.  Calculating the speed over several trials provides adequate practice of measuring distance, time and calculating speed.  The students record data using a chart and line graph. Predictions were made based on the data presented by the group.  It does take time for the students to construct racers that are durable and effective.  This lesson can be presented in two sessions: the first to construct the racers and the second to calculate the speed, record data, make predictions and conduct the final race.

References:

Kahan, Peter.  Science Explorer: Motion, Forces and Energy.  Prentice

Hall: 2000.

# The Great Tin Race

#### Racer Data Sheet

Group Color: ____________________________

Racer’s Name: ___________________________

 Trial Distance Time Speed (Distance/Time) 1 1 m 2 1 m 3 1 m Totals xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx 1 2 m 2 2 m 3 2 m Totals XXXXXXXXXXXXXXX XXXXXXXXXXXXXXX

Average speed at 1 m=            Total distance = ___________________

Total time

Average speed at 2 m=            Total distance = ___________________ (This data will be recorded

Total time                                                        on the large group chart) ### The Tin Can Racer Blueprint 1.      Cut off the bottom of an empty coffee can with a can opener.

(This part was done for you!  I even filed the metal edges with sandpaper.)

2.      Use scissors to punch a hole in the center of both coffee can lids.  The holes must be just large enough for a rubber band to pass through.

3.      Push one end of a rubber band (a thick one) through one of the holes and hook it around a paper clip on the outside of the lid.  Tape the paper clip in place, over the hole, so that the rubber band cannot pull through the hole.  Place the lid with the rubber band on the can.

4.      Reach into the can and grab the rubber band (be careful of the edges).

5.      Push the free end of the rubber band through the hole in the other lid from the inside.  Slip the end of the rubber band through a bead so that the bead is on the outside of the lid.

6.      Slide a pencil through the part of the rubber band that is on the far end of the bead from the can, so that the pencil stops the rubber band from pulling back through the bead and the lid.

7.      Adjust the position of the pencil so that the end of it extends past the edge of the can.

Note: If it is too short, get a longer pencil!

8.      Wind up the pencil until it comes back to you freely and put the can on the floor.  Let go!

To construct the raceway:

Use masking tape to mark your reference point.

Measure 1 meter from the reference point and use masking tape to mark it.  Measure 2 meters from the reference point and use masking tape to mark the end point.

Note: Be sure to record the distance and time traveled on the racer data sheet.

Group __________________________________

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(m)

Motion Graph

 2.5 2.0 1.5 1.0 0.5

1           2           3           4           5           6           7           8            9          10         11         12         13          14

Time (sec)

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