Materials List:
Does Contact Area Matter?
https://www.teachengineering.org/activities/view/duk_friction_smary_act3
- spring scales, preferably having a 500 g capacity and 5-10 g accuracy, one per team of 2 to 4 students; Ohaus makes one that works well for this exercise; it is available from suppliers such as Ward for about $6
- ceramic coffee mugs, one per team of 2-4 students (ask students to bring these from home or purchase them from thrift stores)
- scissors (one per team)
- tape (masking or wide transparent), one roll per team or one roll shared between two teams
- string, about 30 cm per team
- cardboard or poster board, enough for about 1 square foot per group
- Styrofoam™ picnic plates, about four per group, and/or stiff glossy paper, laminated paper or overhead transparency plastic; enough for 1-2 square feet per group
- rulers, one per group
https://www.teachengineering.org/activities/view/duk_friction_smary_act3