The van speeds up, holds a steady speed, then slows to a stop. The distance it covers is the area under the speed-time line, split into a triangle, a rectangle and a triangle. Shape the journey so the van stops on the checkpoint, then run it and watch the area fill in real time. The dashed box is the tempting wrong shortcut: peak speed multiplied by total time, which always overshoots.
MissionStop the van on the checkpoint at 200 m. Shape the area to match.Round 1Streak 0Best 0
Predict the stop:
triangle 1, speeding up30 m
rectangle, steady120 m
triangle 2, slowing30 m
true distance, total area180 m
wrong shortcut, peak × time240 m
area = ½(5)(12) + (12)(10) + ½(5)(12) = 30 + 120 + 30 = 180 m