Square Pursuit Puzzle - Solution
The Puzzle:
Each person moves at the same speed directly towards the next person counterclockwise as seen from above.
As a result, they spiral in until they all eventually collide at the center of the square. How far has each person traveled?
Our Solution:
If you stand still and someone moves continuously at right angles to the line between you, that person describes a circle around you. So their motion doesn't change the distance between you at all!
In the pursuit problem, in each person's frame of reference, the target person is always moving at right angles to the target line.
So if the initial distance each person would have walked is 10 meters, then that's the distance they eventually walk to meet: just 10 meters.
In the pursuit problem, in each person's frame of reference, the target person is always moving at right angles to the target line.
So if the initial distance each person would have walked is 10 meters, then that's the distance they eventually walk to meet: just 10 meters.
Puzzle Author: Dave Grossman
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