Escape Velocity

Introduction

 Velocity is an important part of physics. Students aspiring to become engineers, especially the ones who aspire to become aerospace engineers must have a clear idea of what escape velocity is. Competitive examinations like GATE ask questions about escape velocity and therefore, to score well in such examinations clear understanding of the concept of escape velocity is very important. 

What is Escape Velocity?

According to astronomy and exploration of space, escape velocity is the adequate amount of velocity that a body must possess to escape from the central attraction of gravity without going through any further process of acceleration. Escape Velocity reduces the height and it is the same as the square root of two or it is almost one thousand four hundred and fourteen times the adequate velocity sufficient enough to maintain a circular shaped orbit at a similar height. If atmospheric resistance was possible to be disregarded at the surface of the Earth then the value of escape velocity would have been approximately eleven kilometers per second. From the comparatively smaller surface of the moon, the escape velocity equals approximately 2.4 kilometers per second. A satellite or planet cannot retain an atmosphere long enough if the velocity of escape of that planet or satellite is not quite low enough to match the mean velocity of molecules of gas that makes up the atmosphere. Rocket science and space travel require the concept of velocity of escape as it helps to find the escape velocity of an object needed to escape from the gravitational pull of the orbit of a celestial body.  

How does the escape velocity function? 

Almost like the functionality of orbital velocity, the velocity of escape changes according to the distance between any given object from the center of gravity. In more simple words the working of escape velocity can be explained by giving an example. The more altitude a rocket gains, the lesser amount of velocity will be required to orbit the Earth. The major reason why communication satellites are easily able to orbit the Earth without the need for constant expenditure of energy is, they can subsist the high kilometers away from the Earth. On the contrary, a commercially used airplane that travels much closer to the surface of the Earth should exert a constant amount of force in the sky. However, adhering to the basic principles of escape velocity, a rocket requires a much lower amount of energy to gain escape velocity compared to a rocket that would have flown closer to the surface of Earth. 

How to calculate the Escape Velocity of any given object? 

The velocity of escape is a function of the orbital velocity of a given object. If the velocity that is adequate to maintain orbit at a given height is multiplied by the square root of two (that is around one thousand four hundred and fourteen), the determination of the adequate velocity to escape the orbit and the field of gravity that is responsible for controlling the orbit, is possible. 

In simpler words, suppose there is a spaceship that is launched and it reaches the orbit and starts to move along the orbit. If the spaceship fires the engine then it will start to move fast. Gradually it will reach the speed at which it will be fast enough to move deeper into space. Soon, it will be out of reach from the Earth’s gravitational pull. The specific speed is known as the velocity of escape. That speed is forty-one percent faster than the speed of the orbit. 

Conclusion

Escape Velocity is an important concept and it holds a lot of importance in the field of astronomical engineering and aerospace engineering. Without the proper determination of escape velocity, it would not have been possible for humankind to achieve the success of reaching the moon. Artificial satellites are launched into space after the calculation of escape velocity. Thus, in the absence of this concept launching satellites would not have been possible as well.