Universal gravitation and oil well: what they have in common
- Step 1. Universal gravitation — is used in — Pile driver. A falling weight.
- Step 2. Pile driver — has part — Block and tackle. Lifting the weight.
- Step 3. Block and tackle — is part of — Drilling rig. The block and tackle lifts the drill string.
- Step 4. Drilling rig — is used in — Oil well. A well is drilled by a rig.