Ladder
device · 10000 BC · Stone Age
Rungs between two uprights.
What it is made of
- Ladder side rails — has part. Two lengthwise uprights.
- Ladder rungs — has part. Rungs for the feet.
Principles and materials it uses
- Inclined plane — uses. Climbing to a height.
- Wood — is made of. Ladders were made of wood.
- Friction — uses. The feet hold on the floor by friction.
Where it is used
- Scaffolding — is part of. Ladders between the levels.
- Fire truck — is part of. An extending ladder.