Unbalanced forces: the pull-back racer
Inventors (Intermediate), mission I1 Forces & Motion, lesson 1 of 6.
Hook
Why does a still car start moving? Something must be pushing… but what?
Fair test
Draw force arrows before and after release. Measure distance for 3 pull-back lengths.
Bonus challenge
Use arrows made of sticky notes on the table to show the forces during a run.
The build
🏁 Pull-back Racer: Pull it back, let it go — ZOOM! A racer with a spring for an engine. (level 2 of 5, about 12 minutes, 10 steps)