Why do rockets need to fly at speed greater than 11.81 km/s (escape velocity)?

Question

Isn’t going up with velocity greater than 9.81 m/s be enough to escape earth’s gravity?

In: Physics

Answer 1

* 9.8 m/s^(2) is the acceleration produced by the force of earth’s gravity. It is not a velocity. Rockets have to produce sufficient force in the opposite direction to overcome that velocity, regardless of what speed they wind up going.
* Rockets don’t have to exceed escape velocity to escape the earth. Escape velocity applies to ballistic objects (like a cannonball), not objects that are constantly applying force.