Mint-Mobiles

Students design, build and test model race cars made from simple materials (lifesaver-shaped candies, plastic drinking straws, Popsicle sticks, index cards, tape) as a way to explore independent, dependent and control variables. They measure the changes in distance travelled with the addition of mass to the vehicles. Students also practice the steps of the engineering design process by brainstorming, planning, building, testing, and improving their "mint-mobiles."

Weblink address (URL): 
Mint-Mobiles

Standards & Objectives

Learning objectives: 

Learning Objectives

After this activity, students should be able to:

  • Explain the steps of the engineering design process.
  • Identify dependent and independent variables.
  • Identify control variables

Lesson Variations

Blooms taxonomy level: 
Understanding
Extension suggestions: 

Activity Extensions:

Team Test Your Instructions: In addition to each team designing a mint-mobile with a sketch and list of materials, have them write instructions on how to build the mint-mobile and exchange designs with another group. Tell the students to build the other team's mint-mobile following the instructions using only the supplies listed. This exercise sharpens students' awareness of the importance of accuracy and clear communication in their engineering plans. Or similarly, conduct The Universal Language of Engineering Drawings activity, in which students practice the ability to produce clear, complete, accurate and detailed design drawings for a mint-mobile-type model car, using only specified materials. Teams trade drawings and attempt to construct the model cars in order to determine how successfully the original design intentions were communicated through sketches, dimensions and instructions.

Helpful Hints

Materials:

Each group needs:

  • Note: for mint-mobile construction supplies, the exact amounts required depend on the team's vehicle design; rough estimates are provided
  • plastic drinking straws (estimated 4-6; make sure the straw diameter is smaller than the mint candy's hole diameter)
  • Popsicle sticks (estimated 2-4)
  • lifesaver-shaped candies, such as Lifesaver® mints (estimated 3-6)
  • index cards (estimated 1-2; or thin cardboard or poster board scraps)
  • tape, any type; duct or masking preferred
  • scissors
  • paper and pencil

For the entire class to share:

  • ramp, for testing, made from sturdy poster board, rigid cardboard or thin wood
  • meter stick, for measuring the distance traveled
  • pennies, for added mass during testing (estimated 10-30 pennies; depending on robustness of mint-mobiles, individually tape pennies on vehicles, or tape a little baggie or film canister of pennies
  • tape, for securing the ramp, meter stick and pennies
  • (optional) hot glue gun and glue sticks (requires adult supervision)

References

Contributors: 
Virginia Cooter
Originator: 
Ayers Institute for Learning & Innovation