Yard per Second to Millimeter per Hour

Yard per second measures distance in yards traveled in one second.

1 yd/s = 0.9144 m/s = 3.29 km/h = 2.045 mph = 3 ft/s.

To ft/s: × 3. To m/s: × 0.9144. To mph: × 2.045.

Sprint speeds in track and field (10–12 yd/s for elite sprinters), projectile velocities, and some fluid flow measurements.

Usain Bolt peak: ~13.5 yd/s. NFL wide receiver sprint: ~11 yd/s. Baseball thrown: ~40–45 yd/s.

Confusing with ft/s — yd/s is 3× faster. Mixing up with mph.

1 yd/s = 3 ft/s = 0.9144 m/s. Multiply by ~2 to get approximate mph.

Millimeter per hour measures extremely slow movements in millimeters over an hour. Used for minute geological and material changes.

1 mm/h = 0.001 m/h = 0.0000001 km/h = 0.000000278 m/s.

To m/s: ÷ 3,600,000. To cm/h: ÷ 10. To m/h: ÷ 1,000.

Cave formation rates (stalactite/stalagmite growth), extremely slow material creep, and long-term geological monitoring.

Stalactite growth: 0.1–1 mm/h in active caves. Human hair growth: ~0.015 mm/h. Fingernail growth: ~0.004 mm/h.

Using for anything except the slowest processes. Confusing with mm/min (60× faster).

1,000 mm/h = 1 m/h. Extremely specialized unit. Think geological time scales.