Final answer:
When a trailer bounces up and down slowly while being towed, it is more likely to be heavily loaded rather than nearly empty. The bouncing motion is caused by the weight of the load shifting within the trailer, resulting in noticeable bouncing. Heavily loaded trailers will experience more significant weight shifts, causing more noticeable bouncing.
Step-by-step explanation:
When a trailer bounces up and down slowly while being towed, it is more likely to be heavily loaded rather than nearly empty. This is because the bouncing motion is caused by the weight of the load shifting within the trailer, resulting in the trailer's suspension system reacting to the changes in weight distribution. A heavily loaded trailer will experience more significant weight shifts, causing more noticeable bouncing.