Author of this question: Steffi Knorn, Fachgebiet Regelungstechnik, Technische Universität Berlin, Germany
Santa wants to make Christmas extra special for kids in Australia by creating an upside-down Christmas tree. However, the unusual design keeps tilting over, and without a solution, the kids down-under might lose their festive cheer. To tackle the issue, Elf Shaz built a magical kart capable of moving in any direction—left, right, forward, or backward—and designed to sense the tree’s tilt. The situation sparked a heated debate in the workshop: how should Santa use the kart to keep the tree balanced?
By the way: Elf Ava suggested trying to balance a broomstick or pen on their hand as an experiment to better understand the problem. On the other hand, Elf Hans, ever safety-conscious, warned them to exercise caution to avoid accidents or breaking things. Maybe that’s some good advice to follow? What do you think?
a. 🎄🔗🚜 Santa should instruct the kart to move right, left, forward, or backward whenever the Christmas tree tilts in that direction. This will solve the problem of balancing it on the spot. For situations where the tree needs to be relocated, attach a chain to the kart. This way, it can be pulled along while carefully adjusting the speed and direction to maintain balance during the movement.
b. 🎄➖🚜 Santa should instruct the kart to move right, left, forward, or backward whenever the Christmas tree tilts in that direction. For situations where the tree needs to be relocated, attach a bar to the kart. This allows for an initial push in the opposite direction of the intended movement before pulling it along. Be sure to carefully adjust the speed and direction while pulling to maintain balance during the relocation.
c. 🎄📦❌ Santa should use the kart to balance the tree in place as described earlier. However, there is no way of moving the tree around. Since the kart cannot be used to move the tree, the delivery will need to be organised differently, probably with the tree being transported in a box as usual.
d. 🎄🏠🔄 Santa should use the kart to balance the tree on the spot, as described earlier. Luckily, this will only be necessary during the installation of the tree in Aussie homes. After a few minutes, the kart can be removed and reused in the next house.
e. 🎄🔩🛠️ Santa should ask Elf Billy to secure the tree to the kart using nuts, bolts, and sturdy steel. It’s the only reliable solution to ensure the tree stays in place.
f. 🎁🚜🎉 Santa should gift the kart to the kids in Australia. While it may not solve the problem of the upside-down Christmas tree, the kart itself would make a wonderful present.
g. 🎄🏄🎁 Santa should skip the kart and gift surfboards instead: they are perfect for an Aussie Christmas!