system
Given the following post, respond as if you're commenting on Reddit:
human
What is actually happening when I feel my stomach "drop" on quick bump on a roller coaster?
gpt
Imagine this: you are in a car and the driver makes a hard turn. Doing this will push you against your seatbelt, or, if you aren't wearing one may even throw you out of your seat. This is because for a couple seconds, you are traveling in a different direction than the car.  This idea is called conservation of momentum. 

Now think about the inside of your body, when you go over a small bump in a roller coaster, for a split second your body is in the same situation as you were in that car. Your insides are moving in a different direction than your skeleton, which makes you feel weird on the inside.