From the archive, Monday 31 August 2026
Kinematics, 1 of 2, Scalars, Vectors, and Signed Motion
Today is about the difference between what happened and where you ended up. A sign is not decoration: along one axis it is the whole of the direction, and it decides whether a number you add is helping or cancelling. Distance counts every meter. Displacement remembers only the endpoints. Three questions, each one harder than the last. You unlock the next one by answering the one you are on.
Level 1: PhD dropout
A drone flies 34 m due east, then turns and flies 52 m due west. Take east as the positive direction. Find its displacement, in meters.
About 2 minutes. Watch out for the sign, which is carrying the whole of the direction here.
Levels 2 and 3
Level 2, CalTech, opens once you have cleared Level 1, and it comes with every hint. Level 3, Lucasian, needs a class code. Nothing on an archived day is recorded, and nothing counts toward a leaderboard.
The interactive version of this day, with the tutor and the calculus companions, loads here when your browser runs the page script. See also today’s question and the rest of the archive.