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**Department of Mathematics Education**

Rate and Distance

J. Matt Tumlin

Students will measure the time required for
battery-powered cars to travel a measured distance, and calculate the speed of
the cars. Based on the comparisons, a
winner of the race will be predicted. An
actual race will test the validity of the prediction.

To motivate students,
discuss how speed can be measured in a car.
How would you measure your speed if the speedometer were broken? Next, discuss formulas, rearranging formulas,
rounding, and averaging. Adjust the
distances for your races, if necessary.

For a Microsoft Word copy, CLICK HERE.

Place a 1-foot piece
of tape on the floor as a starting line.
Measure 15 feet and place another 1-foot piece of tape for a finish
line. Form a team to work with each car. Each team should measure the time required
for its car to go from the starting line to the finish line. Write this time on a sheet of data
paper. Repeat and record the
measurements for a total of five trial runs for each car. Use an appropriate formula to calculate the
speed of the car for each trial run in feet per second (ft/sec). Round each answer to the nearest hundredth of
a foot per second. Calculate the average
speed of the car for the five trial runs to the nearest hundredth of a ft/sec. When all groups have finished recording
results, compare the average speeds and predict which team’s car will win a
race. Measure a distance of 25
feet. Race the cars over the 25-foot
distance. Record which cars take the
first three places. How do the results
of the race compare with the predictions made?

This problem has many
aspects you can go into, data measurement, substitution, and evaluation of
formulas, and use of technology. It also
has many entry and exit points.