system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:How do rollercoaster designers account for the varying weight of passengers?

It occurred to me that a rollercoaster in freefall would behave very differently if it was full of really skinny people as opposed to if it was full of much larger people. How do the designers account for the potentially massive difference in passenger weight?
gpt
They test the ride under two conditions: Unloaded and massively overloaded. The train has to be able to complete the ride fully with both completely empty seats and then with the scenario where each seat is loaded with 400lb crash test dummies.