World 2 · Gears & Pulleys · 6 min · PROMeet the Gear
Toothed wheels that pass on turning force
PRO · Simple Machines
World 2: Gears & Pulleys is part of PRO
The first world of Simple Machines is free. PRO opens the other 32 lessons in 6 worlds — simulations, quizzes and all.
PRO includes
- All 26 labs — every world, every lesson
- Practice exams and certificates
$8.33/mo, billed yearly ($99.99) · or $39.99 monthly