Convert Kilometer/Hour (km/h) to Cosmic Velocity - Second (v₂) instantly.
About these units
Kilometer/Hour (km/h)
The kilometer per hour is a widely used everyday speed unit, especially in transportation. Most countries use km/h for automobile speed limits, train speeds, and vehicle specifications because it aligns naturally with metric distances. Although less mathematically convenient than m/s, km/h provides a human-friendly scale: speeds of 30–120 km/h correspond well to familiar travel activities. Converting between the two units is straightforward (1 m/s = 3.6 km/h), allowing scientists to work in m/s while communicating results in km/h. The use of km/h reflects society's need for intuitive, coarse-grained measurements while maintaining compatibility with scientific standards. Its ubiquity makes it one of the world's most recognized speed measures.
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.