## How Fast Is Your Car?

### Kenneth BlackmanSanta Rosa District Schools

#### Description

In this lesson, students discover the relationship between speed, distance, and time. They calculate speed and represent their data graphically.

#### Objectives

The student knows the appropriate operations to solve real-world problems involving integers, ratios, rates, proportions, numbers expressed as percents, decimals, and fractions.

The student solves real-world problems involving integers, ratios, proportions, numbers expressed as percents, decimals, and fractions in two- or three-step problems.

The student applies formulas for finding rates, distance, time and angle measures.

The student describes and uses rates of change (for example, temperature as it changes throughout the day, or speed as the rate of change in distance over time) and other derived measures.

The student reads and interprets data displayed in a variety of forms including histograms.

The student constructs and interprets displays of data, (including circle, line, bar, and box-and-whisker graphs) and explains how different displays of data can lead to different interpretations.

#### Materials

- Match-Box Cars-- 48 cars
- Books ( Books needed for ramp)
- Paper
- Pencils
- Cardboard--Squares or strips
- Yard or meter sticks
- Calculators
- Stopwatches
-Scales

#### Preparations

1. Cut out all needed car ramps from cardboard. Approximately 1 meter in length and 12 inches wide.
2. Have stop watches and yardsticks placed in the classroom.
3. Place the formula Speed= Distace Divided by Time on the board.

#### Procedures

Day 1.
1. Discuss with the students the difference between constant and average speed. Discuss graphic illustrations of linear motion as distance divided by time. Discuss the difference between speed and velocity.
2. Review the formula Speed= Distance/ Time.
3. Model problems on the board relating to the above formula. Also model the concept of graphing a linear equation.
4. Distribute and assign the review worksheet. Circulate through the classroom to check for comprehension.
5. Review the concepts discussed during the class period. Question students and work example problems checking for comprehension.
Day 2:
1. Review the formulas and concepts introduced the day earlier.
2. Arrange the class in groups of four. (The groups can be students or teacher selected.) Have students select someone from the group to record data.
3. Give the students the three data sheets and the materials for the lab activity.
4. Instruct the students to construct a ramp for their cars. They are to measure the length and height of each ramp, and the length of time it takes for each of the three cars to travel down the ramps. Each car should also be weighed on a triple beam balance. All measurements are to be recorded on the data sheets.
5. After making all measurements,the students should use the recorded data to calculate the speed of each car.
6. After calculating the speed for each car on three different ramps, tell the students to graph all data on nine seperate bar graphs. Then to combine the data on one graph comparing each car to the other.
7. Have each group present their data to the class.

#### Assessments

The students will be assessed using the review worksheet and the data collection forms. The problems on the review worksheet will be graded for correctness and the data collection form will be checked to insure calculations were done correctly.

#### Extensions

This activity could also be used to discuss acceleration.

#### Attached Files

Both the data sheets and the review worksheet.     File Extension: pdf