Newton's in the Driver's Seat

Purpose: To learn about Newton's Third Law of Motion: For every action there is an equal and opposite reaction

Materials (per group)

• 2 identical plastic toy cars
• metric ruler
• smooth, flat surface
• science journal
• pencil

Procedure

1. Working in pairs, on a clean, smooth, flat surface, place cars 60 cm apart so they are directly facing each other.
2. Each student will gently push his/her car towards the other car at a designated time indicated by a countdown of 3-2-1, go.
3. Observe and note the point on the surface where the cars made contact, and once the cars come to a stop, mark that point, being careful not to move the cars.
4. Measure the distance each car traveled from the point marked and record in your science journal.
5. Repeat for at least three more trials.
6. In your science journal, write a description of what happened as the cars were pushed, made contact, and finally stopped.

Conclusion

1. What happened after the cars made contact?
2. Explain why it happened.
3. What would happen if you applied a greater force when pushing the cars?

Extension

1. Apply different forces to the car and compare the results.
2. Add various amounts of weight (pennies or washers) to the cars and compare what happens.