Thursday, 31 July 2014

// // Leave a Comment

WHAT IS ESCAPE VELOCITY

escape velocity is the speed at which the kinetic energy plus the gravitational potential energy of an object is zero. It is the speed needed to "break free" from the gravitational attraction of a massive body, without further propulsion, i.e., without spending more fuel.
For a spherically symmetric body, the escape velocity at a given distance is calculated by the formula
v_e = \sqrt{\frac{2GM}{r}},
where G is the universal gravitational constant (G = 6.67×10−11 m3 kg−1 s−2), M the mass of the planet, star or other body, and r the distance from the center of gravity.
In this equation atmospheric friction (air drag) is not taken into account. A rocket moving out of a gravity well does not actually need to attain escape velocity to do so, but could achieve the same result at any speed with a suitable mode of propulsion and sufficient fuel. Escape velocity only applies to ballistic trajectories.

The term escape velocity is actually a misnomer, and it is often more accurately referred to as escape speed since the necessary speed is a scalar quantity which is independent of direction (assuming a non-rotating planet and ignoring atmospheric friction or relativistic effects).
If You Enjoyed This, Share this article with your Friends

0 comments:

Post a Comment