# 8. A Test Drive

## Overview

Students compare their cars with one another’s cars, by rolling them down ramps to see what happens. They develop vocabulary to describe what happens.

## Materials

• Students’ cars from Lesson 7
• For each pair of students: a Ramp and ramp stand for testing cars.

## Procedure

1. How did it work?
Review what has happened so far: students have had ramps that a sled wouldn’t go down. They helped the sled go down by putting rollers underneath, but at the bottom of the ramp, the rollers broke loose, and the sled couldn’t keep going. Finally, they invented ways to attach round things, wheels, to the sleds. These ways allowed the wheels to turn, but not leave the sled. This turned the sled into a car.

• What’s an experiment we can do to see how our cars compare with each other?
• Model an experiment for them, by comparing two cars made in Lesson 7:
• Which car will go furthest
• Which one will go straightest?
• Use a class chart to record results. Generate more questions that could be tested. Then have students pick a partner and a question that they want to test. After doing the experiment with a partner, discuss briefly what happened.

2. Comparing cars.
As the students are testing their cars against each other, help them develop language for comparing the results:

• Some cars go straight, but other cars go in curves.
• Some cars go far, but some don’t go as far
• Some cars stay together, but some come apart.

3. Storage:
Make sure each car is labeled with stored in a plastic bag, as in Lesson 7.

4. Science Notebook: