Convert Walking Speed (walk) to Cosmic Velocity - Second (v₂) instantly.
About these units
Walking Speed (walk)
The average human walking speed is about 1.2–1.4 m/s (4–5 km/h), though this varies with fitness, terrain, age, and purpose. Walking is an energy-efficient mode of locomotion optimized through millions of years of evolution. Humans unconsciously adjust stride frequency, step length, and posture to maintain stability and minimize metabolic cost. Urban planning, pedestrian-safety engineering, and architecture all use walking-speed estimates to design sidewalks, crosswalk timing, and public transportation access. Walking speed is not merely a physical measure—it reflects physiology, psychology, and cultural context.
Cosmic Velocity - Second (v₂)
The second cosmic velocity is the escape velocity, the speed required to completely overcome a planet's gravitational attraction without further propulsion. For Earth, this speed is about 11.2 km/s. It is higher than v₁ because escaping gravity requires exceeding orbital balance entirely, not merely achieving stable free fall. Escape velocity underlies missions to the Moon, other planets, and deep space probes. Reaching v₂ allows spacecraft to travel along trajectories that leave Earth's gravitational well permanently unless acted on by external forces. This value symbolizes humanity's ability to break free from its home world—a critical milestone in exploration.