Yacht and fitness tracker: what they have in common

1. Step 1. Yacht — has part — Keel. A keel.
2. Step 2. Keel — uses — Archimedes’ principle. The keel and ballast provide stability.
3. Step 3. Archimedes’ principle — is used in — Weather balloon. A balloon filled with hydrogen or helium.
4. Step 4. Weather balloon — is made of — Vulcanized rubber. The envelope is rubber or latex.
5. Step 5. Vulcanized rubber — is material for — Fitness tracker. The strap is silicone.

Open Evothings