escape velocity

noun

, Physics, Rocketry.

1. the minimum speed that an object at a given distance from a gravitating body must have so that it will continue to move away from the body instead of orbiting about it.

escape velocity

noun

1. the minimum velocity that a body must have in order to escape from the gravitational field of the earth or other celestial body

escape velocity

/ ĭ-skāp′ /

1. The velocity needed for a celestial body to overcome the gravitational pull of another, larger body and not fall back to that body's surface. Escape velocity is determined by the mass of the larger body and by the distance of the smaller body from the larger one's center. Depending on its initial trajectory, a smaller body traveling at the escape velocity will either enter a periodic orbit around the larger body or recede from the surface of the larger body indefinitely. The escape velocity at the Earth's surface is about 11.2 kilometers per second (25,000 miles per hour); the escape velocity on the Moon's surface is 2.4 kilometers per second (5,300 miles per hour). The escape velocity within the event horizon of a black hole is higher than the speed of light; since nothing can exceed the speed of light, nothing—even light—can escape from within the event horizon of a black hole.

escape velocity

1. The speed an object must reach to escape the pull of gravitation exerted by another object.

Notes

To overcome the gravitation of the Earth and place an artificial satellite in orbit , a rocket must reach a speed of about 25,000 miles per hour, or about seven miles per second.

Word History and Origins

Origin of escape velocity¹

First recorded in 1950–55