1. The boat rocked so much that I got sick.
2. The boat rocked much enough for me to get sick.
(Does #1 mean #2? Are both the same?)
3. The sound was from an iceberg which was breaking up.
(Why do we have to use 'up' after 'breaking'? Can't we use 'breaking' alone?)
The first one is fine; the second doesn't make any sense.
In number 3, we need to use "up."
1. Yes, both sentences convey the same meaning. Sentence #1, "The boat rocked so much that I got sick," means that the boat's rocking motion was intense enough to cause the speaker to feel sick. Sentence #2, "The boat rocked much enough for me to get sick," is a less common phrasing but still conveys the same idea - that the rocking motion of the boat was sufficient to make the speaker feel ill.
2. In the sentence "The sound was from an iceberg which was breaking up," the use of "up" after "breaking" is necessary to convey the complete action. "Breaking up" means that the iceberg is breaking apart or disintegrating into smaller pieces. The addition of "up" in this context indicates that the iceberg is breaking into pieces in an upward direction, potentially creating sounds as it does so. Without "up," the sentence would not fully describe the action of the iceberg disintegrating and the resultant sound.