Standard kilogram and electric motor: what they have in common

1. Step 1. Standard kilogram — is made of — Platinum. A platinum–iridium alloy.
2. Step 2. Platinum — is material for — Fuel cell. A platinum catalyst.
3. Step 3. Fuel cell — is part of — Hydrogen car. A fuel cell.
4. Step 4. Hydrogen car — has part — Electric motor. An electric motor.

Open Evothings