Final answer:
Unstable objects cannot be used to support scaffold legs as it is unsafe and goes against safety guidelines requiring stable support.
Step-by-step explanation:
The answer to whether unstable objects can be used to support scaffold legs is false. Scaffold legs must be placed on stable, level, and solid footing to ensure the safety of the structure and the workers using it. Scaffolding is a temporary structure used in construction and should be erected according to strict safety guidelines, which require stable support for sustaining the loads that will be placed upon it. Using unstable objects could lead to catastrophic failure, causing potential injury or even death.