Cosmic Velocity - Second to Centimeter per Hour

The second cosmic velocity (Earth's escape velocity) is approximately 11,200 m/s (11.2 km/s), the minimum speed to escape Earth's gravity completely.

v₂ = √(2GM/r) = √2 × v₁ ≈ 11.2 km/s. Exactly √2 times the first cosmic velocity.

To km/h: × 3,600. To mph: × 25,000. 11.2 km/s = 40,320 km/h = 25,053 mph.

Moon missions, Mars missions, deep space probes (Voyager, New Horizons), and any mission leaving Earth's gravity well.

Apollo missions: ~11.2 km/s. Voyager probes: exceeded v₂ to leave solar system. New Horizons: launched at record 16.26 km/s (fastest ever from Earth).

Thinking you need this speed everywhere — you only need it at launch. In space, much less Δv is needed.

~11 km/s to escape Earth. √2 × orbital velocity. Remember: orbit ≈ 8 km/s, escape ≈ 11 km/s.

Centimeter per hour measures very slow movements in centimeters over an hour. Used for extremely gradual processes.

1 cm/h = 0.01 m/h = 0.00001 km/h = 0.00000278 m/s. Extremely small speed unit.

To m/s: ÷ 360,000. To m/h: × 0.01. To mm/h: × 10.

Very slow geological processes, material expansion/contraction measurements, and some biological growth studies.

Human nail growth: ~0.01 cm/h. Stalagmite formation: ~0.001 cm/h. Some coral growth: 0.1 cm/h.

Using for anything except very slow processes. Confusing with cm/min or cm/s.

100 cm/h = 1 m/h. Primarily a scientific measurement unit. Not for everyday use.