Millimeter per Second to Kilometer per Second

Millimeter per second measures distance in millimeters traveled in one second. Used for small-scale movements and precise measurements.

1 mm/s = 0.001 m/s = 0.0036 km/h = 0.06 m/min.

To m/s: ÷ 1,000. To cm/s: ÷ 10. To km/h: × 0.0036.

Vibration measurements (machinery typically 0.1–50 mm/s RMS), small motor speeds, precision linear actuators, and tape/film transport speeds.

Machinery vibration: >10 mm/s indicates problems. Seismic activity: 0.001–100 mm/s. CD/DVD read head: 1.2–1.4 mm/s linear velocity.

Confusing mm/s with cm/s (10× different) or m/s (1000× different).

1,000 mm/s = 1 m/s. Very common in vibration analysis. 10 mm/s RMS is a typical machinery vibration threshold.

Kilometer per second measures how many kilometers an object travels in one second. Used for very high-speed phenomena like spacecraft, asteroids, and planetary motion.

1 km/s = 1,000 m/s = 3,600 km/h. There are 1,000 meters in a kilometer.

To m/s: × 1,000. To km/h: × 3,600. To mph: × 2,237.

Earth's orbital speed: 29.78 km/s. Moon's orbital speed: 1.02 km/s. Space shuttle orbital speed: 7.8 km/s. Meteor entry: 11–72 km/s.

Solar system escape velocity: 42 km/s. Voyager 1 speed: 17 km/s. Fastest star (S4714 near black hole): 24,000 km/s (8% light speed).

Underestimating the scale — 1 km/s is 3,600 km/h, extremely fast. Confusing with m/s (1000× smaller).

Think of km/s as 'space speeds.' Earth orbits at ~30 km/s. To escape Earth: 11.2 km/s. Moon orbit: ~1 km/s.