Final answer:
The bouncing of a truck's trailer can indicate whether it is heavily loaded or nearly empty.
Step-by-step explanation:
The bouncing of a trailer could indicate whether it is heavily loaded or nearly empty. If the trailer is heavily loaded, it will have a higher inertia, which means it will take more force to make it bounce. On the other hand, if the trailer is nearly empty, it will have a lower inertia and be more prone to bounce easily.