Convert Kilometer/Hour (km/h) to Cosmic Velocity - Third (v₃) 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 - Third (v₃)
The third cosmic velocity is the speed required to escape the entire Solar System from Earth's orbit, overcoming the gravitational pull of the Sun. This speed is approximately 16.7 km/s, though missions often achieve this gradually using gravitational assists rather than brute-force acceleration. Space probes such as Voyager 1, Voyager 2, and New Horizons have exceeded v₃, making them interstellar travelers. The third cosmic velocity represents the threshold where an object ceases to be bound to the Sun and begins drifting through the galaxy—one of the most profound expansions of human technological capability.