Author of this question: Anthony Rossiter, School of Electrical and Electronic Engineering, University of Sheffield, England
Santa’s elves are packing the sleigh to the brim, but now they face a challenge, as the only way out of Santa’s workshop is to pass under a bridge. Outside the bridge, there’s a sign indicating that it’s 4 meters high. However, an unexpected issue has come up recently: the freezing and expansion of the ground beneath the bridge during the cold winter nights pushed up the whole road surface underneath the bridge. The road inside the bridge forms a 20 centimeters bump, which the sign doesn’t account for. This bump will cause the sleigh to bounce up and down as it passes through. The suspension hasn’t been revised in ages, so it takes a hilariously long time for the sleigh’s wild oscillations to settle. But do the elves mind such oscillations? Not at all! They actually enjoy them because they make each ride feel like an amusement park roller coaster. But how shall the elves account for the novel bump underneath the bridge? How high can they safely stack the gifts to avoid a crash that would squash your present — and we all know that’s the most important one?
a. 🍭🎄😋 None of these — I’m only here for the candy canes.
b. 🎁📦🎢 Presents squash, so who cares? Just pack the sleigh as high as possible!
c. 🧝📏🥁 The elves are masters of tight spaces and could stack the sleigh up to 3.8 m. They’ve been doing this for so long, they could probably pack a full drum set into a matchbox — and still leave room for Santa’s snack stash.
d. 🎅✨🪄 Santa is magic, so it doesn’t really matter. He’ll just “Ho ho ho” through it.
e. 📏🎁🛡️ The elves should stack the sleigh no higher than 3.6 m. After all, better safe than sorry when your present is at stake!
f. 📏🔧🎄 The elves can stack the sleigh up to about 3.75 m. While 3.8 m should suffice in theory, it’s wise to allow an extra 5 cm for safety.
g. 🛌🧓💊 My present isn’t important because I’m too old for gifts. The only thing I expect from Santa now is a reminder that I should be in bed by 9 p.m. and maybe a coupon for some multivitamins.