Measuring the Speed of Go-Carts

Sandy Harthan
Centerpoint Elementary School
White Bear Lake, Minnesota
Based on an original activity from the FOSS Kit, Models and Deigns, Investigation 3.

Summary

This activity will enhance the Go-Cart activity of the Models and Designs FOSS unit. Students will make go-carts and measure the velocity, then change different factors of the experiment and see how the velocity changes (examples: adding more mass, adding more of a slope, etc.)

Learning Goals

Students will need to see how changing one variable affects the velocity of the go-cart. They will learn about the equation speed = distance divided by time and practice using it.

Context for Use

This is appropriate for upper elementary students in a classroom setting. Students should work in groups. Allow 2-3 days for this project. If you do not have the Models and Design unit, you can construct the go-carts using your own materials. Each group needs : 2 short sticks, 2 medium sticks, 2 long sticks (I would use ¼ in dowels); 4 wooden hubs, 10 rubber bands, 2 binder clips, 2 paper fasteners, 4 paper clips, 2 clothespins, and a class supply of tape, wire, and cardboard.
This activity comes in during the third investigation of the Models and Design FOSS unit. Students have already been learning about engineering and figuring out how to design something. During this unit, they will be designing go-carts and testing how they work.

Description and Teaching Materials

Activity Description:
1. Students are given a challenge to design and build a cart that can freely roll down a ramp. Do not give them a sample or model; simply give them the materials. It is helpful to have an inventory list in the bag for students to keep track of materials.
2. When teams are ready to test their go-carts, have each group share their design with the class. They can also share problems they are having and ask for solutions.
3. Explain the formula Speed = Distance/ Time. Explain that students will be recording the speed of their go-carts for several trials. Have them create a chart in their notebooks.
Trial Distance Time Speed

4. Students test their go-carts. They will make modifications to their carts if they do not roll freely.
5. Have a class discussion, sharing their designs and comparing the speed of the carts.
6. Day 2: Students experiment with ways to increase or decrease the speed of their go-cart. Ideas: Change the slope of the ramp, add weight to the go-cart, or modify the design of the go-cart. Students will again record the speed of their go-cart.
7. Each group should record their observations on chart paper. Have a class discussion about what happened.
8. Optional: Go on to Part 2 of the Go-Carts activity, Self-Propelled Go-Carts.

Teaching Notes and Tips

Assessment

Students will need to record the speed of their go-carts on the chart in their notebook. Each group will also need to write their observations on a chart. Optional assessment: Teacher could give students a short assessment on the speed equation: i.e. give them the time and distance and have students calculate the speed.

Standards

4.2.1.1.1 Measure temperature, volume, weight and length using appropriate tools and units. (Measuring length)
4.1.2.2.2 Generate ideas and possible constraints for solving a problem through engineering design.

References and Resources