Final answer:
The nylon lanyard attached to a preserver is 9 cm long, providing minimal stretch for safety in climbing scenarios, differing from a bungee cord's elasticity.
Step-by-step explanation:
The length of the nylon lanyard attached to the D-ring or wrist strap on an adult or child preserver is 9 cm. This measurement is critical for safety purposes in climbing gear and is specifically designed to be short so that the lanyard does not offer too much stretch, ensuring that the climber remains close to their anchor point in case of a fall. This distinct characteristic of a nylon lanyard being minimally elastic contrasts with that of a bungee cord, which is designed to stretch significantly to provide a cushioning effect during a fall or jump. In the context of climbing, having a rope or lanyard with minimal stretch is essential as it aids in preventing longer and potentially more dangerous falls.