Combat vehicle and fuel cell: what they have in common

1. Step 1. Combat vehicle — includes — Catapult. A siege engine.
2. Step 2. Catapult — is made of — Sinew. Torsion springs were twisted from sinew.
3. Step 3. Sinew — is material for — Tennis racket. The strings are natural gut.
4. Step 4. Tennis racket — is made of — Carbon fibre. Modern frames.
5. Step 5. Carbon fibre — is material for — Hydrogen car. The tanks are carbon fibre.
6. Step 6. Hydrogen car — has part — Fuel cell. A fuel cell.

Open Evothings