1.)The teacher will write the following terms on the board: force, gravity, and speed. The teacher will activate students' prior knowledge by asking them to tell as much as they can about each of the words.
After listing the students' responses on the board, the teacher will then allow the students to confirm the definitions of the terms by looking each of the terms up in their science textbook glossary and writing the correct definitions in their journals/notebooks.
2.)The teacher will then explain to the students that todays lesson demonstrates a relationship between the three terms found on the board. (force, gravity, speed)
3.) Demonstrate making a ramp by placing one or more books under one end of the plywood. Show students how to gently push the toy car down the ramp and then measure the speed and distance it traveled with a meter stick and stopwatch.(Using the meter stick to measure the distance it traveled and the stopwatch to measure the time it took to travel the distance: start the stopwatch when it begins and stop the stopwatch when it stops.)
4.) Ask students the following question to help them brainstorm ideas: "What makes the car move toward the bottom of the ramp? What keeps it from moving faster?" Allow students to write a response (prediction) in their science journal/notebook.
5.) Divide students into groups of 3 or 4 according to their abilities. The teacher should be sure to group students demonstrating strength in the subject matter with students demonstrating weakness in the subject matter.
6.) Have students help pass out materials.
7.) Allow students time to assemble their ramps and independently explore a bit with their cars, rolling the cars down the ramps. Allow the groups a few minutes to experiment with their ramps, rolling their cars down different height ramps to see what height allows the car to go the fastest and farthest. Ask students: "What does increasing or decreasing the angle of the ramp do for the motion of the car?"
8.)Have groups elect a record keeper to record data and a timer. Explain that each group will conduct 3 experiments which will consist of 3 trial runs.
The first experiment will be to roll the car down the ramp with no added material. Students will record the time it takes for the car to roll down the ramp and how far the car travels for each of the 3 trial runs, and then average (review the steps for averaging) the scores.
9.) After this initial exploration, ask groups to stick to the angle of ramp they found that works the best (best speed and distance for the car) for the remainder of the lesson.
10.) Give each group three pennies, three washers, or other uniform metal objects. Have them all feel one and talk about the weight of it. Then, have them tape two pennies to the top of their toy car. Ask them to hypothesize whether they think this added weight would make the car move faster or slower the car with no added weight. Tell students to again roll the car down the ramp three times, recording the speed and distance for each. Then have them find the average of the three trials. Ask students the following questions: "Did the car move faster or slower with the added weight? Why do you think this is?" Discuss briefly about mass and how it affects speed.
11.) Have students tape the remaining objects (one penny and two washers) to the top of the car. Ask students, "What will happen this time?" Ask them to record their hypotheses in their science journals/notebooks before conducting three more trials. Students should remember to record the speed and distance from each trial and then find the average.
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