🎓 Deeper Dive — Adults

Every Uber/Ola trip calculates this formula in real-time! 📍

The app computes ETA = Distance ÷ Current Speed, updating every second with live traffic data. That's SDT working for you invisibly.

Average speed trap 🚨: Most people think avg speed = (u+v)/2 — that's WRONG for equal distances! The correct formula is 2uv/(u+v) (harmonic mean). This trips up ~60% of CAT aspirants.

Relative speed: Two trains approaching each other at 60 and 90 km/h? Relative speed = 150 km/h — they close the gap 2.5× faster than one alone. Same direction → subtract speeds.

Conversion drill: 18 km/h = 18 × 5/18 = 5 m/s. Memorise: multiply km/h by 5/18 to get m/s.