This was like the BEST QUESTION EVER!
Not only did the Hatian tap-tap aspect broaden our cultural horizons a little, but I've personally experienced crowded Ukrainian marshrutkas - these must be like Cadillacs compared to these tap-taps.
Also, now I know why my car has a rougher ride when it's packed full of stuff for a road trip! I always suspected something was different, and now I know exactly what was going on!
And a spring constant of nearly 30,000N/m?!?! Holy **** that is some kinda restorative force if you could compress that one like the spring in your ball-point pen!
And the chickens and bananas and the goats - so sublime! Like the famous St. Ives riddle, but with physics! LOVED this question.
OK, I have had an energy drink, which is why I might be slightly over-enthused, but this was a pretty sweet question.
I would link to the question set, but you kinda have to be a member of the class to get at them. Anyway, now I know maybe not to load up my car so much next road trip, or maybe take it super easy on the bumps!