Cosmic Velocity - Second to Yard 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.

Yard per hour measures distance in yards traveled over one hour. Rarely used except in specialized contexts.

1 yd/h = 0.000254 m/s = 0.0009144 km/h = 0.9144 m/h.

To yd/min: ÷ 60. To ft/h: × 3. To m/h: × 0.9144.

No common modern applications. Might appear in some historical documents.

No notable facts — too rarely used.

Even existing is a mistake — use m/h, ft/h, or mph instead.

1,760 yd/h = 1 mph. Extremely uncommon. Better to use other units.