일반물리학 1 — Motion Along a Straight Line: Problem 9

9 In 1 km races, runner 1 on track 1 (with time 2 min, 27.95 s) appears to be faster than runner 2 on track 2 (2 min, 28.15 s). However, length \(L_2\) of track 2 might be slightly greater than length \(L_1\) of track 1. How large can \(L_2 - L_1\) be for us still to conclude that runner 1 is faster?