Question
(a) How fast would an athlete need to be running for a 100-m race to look 100 yd long? (b) Is the answer consistent with the fact that relativistic effects are difficult to observe in ordinary circumstances? Explain.
1. $1.21 \times 10^8 \textrm{ m/s}$
2. A race will never be run at speeds even many order of magnitude less than that found in part (a). Extremely high speeds, not attainable for macroscopic objects on Earth, are needed to observe relativistic effects.
Solution Video