Why cant we get out of the gravitional potential field without the escape velocity?

Question

Though my question is stupid, please help me out.........

Why can't I get out of the gravitational potential field without the escape velocity?

Answer 1

You can get out of earths gravitation pull with out reaching escape velocity. However it would be difficult from an engineering standpoint as well as highly inefficient.
The reason why it is called escape velocity is because if you reach that speed while going up in a rocket you will escape the earths gravitational pull. Even if you turn off your rocket engine. (Note; This statement ignores wind resistance.)
I will avoid the complexities o how it is made, but it is based on converting the potential energy if an object was an infinite amount of distance away and converting that in to kinetic energy.

Answer 2

The escape velocity is an abstraction. Yes, it is all correct. It does calculate the velocity required to have gravitiational acceleration reduce it to zero only at the inifinte distance limit. But that is not physical since it discounts all of the other matter out there that influences the gravitational fabric of the universe.

However, in the absence of all of that, if you departed the surface of the earth with less than the escape velocity, at some point, the gravity will have decelerated you to zero and then pulled you back toward the earth. Beyond the escape velocity, it would never have enough influence to stop you.

You don't get out of that potential field. It just cannot stop you. Slow you down? Yes, but never stop you completely.

Answer 3

In a gravitational field work has to be done against the gravitational force to move a mass from stronger to weaker field. We know that gravitational field becomes weaker as we go away from the source, so some work has to be done to move an object away from the center of the earth.
As we go far away from the earth the gravitational field becomes weaker and weaker, eventually it becomes quite negligible so that we can ignore it (though it never becomes a nought). Somewhere far away there is no significant effect of the earth's gravitation. But to go there we have to overcome the gravitation of earth , we have to do work against gravitation.
Energy is the potential to do work and kinetic energy is one form of energy.
When an object is in motion (it has nonzero velocity) it has kinetic energy, which means that the object has the potential to do work.
Now Escape velocity is a velocity which gives us the kinetic energy sufficient enough to do required work against gravitational field of the earth. That's why we can't get out of the gravitational potential field without the escape velocity.

Answer 4

If you were to 'drop' a one pound weight from a satellite toward earth and the earth had no atmosphere (wind resistance), the weight would convert all its potential energy (due to elevation) to kinetic energy (of motion) by the time it reached the ground. This is similar to a pendulum that converts potential energy at the top of its swing to kinetic energy at the bottom (back and forth). The amount of kinetic energy (mass and velocity) that the weight has when it hits the ground is the exact amount of energy you must add to the weight to send it back into orbit (neglecting wind resistance). Either a canon must add all the required energy at the ground (escape velocity) or a rocket must burn fuel and add the required energy en-route to outer space. If there is too little energy the weight will fall back to earth just like a baseball you through straight up above you.

Answer 5

You could climb a ladder at walking pace to do it if the ladder was long enough.

The escape velocity is just the velocity you must have at the surface of the earth to escape with no further input of energy - neglecting air resistance of course.

Answer 6

That's just the velocity you'd need to achieve if all of your acceleration is done quickly in a single short rocket burn, which is what chemical rockets do best. If you slowly spiral out from orbit with a low thrust, long duration rocket, you never have to go that fast. If you went straight up from the north pole like an elevator with continuously burning rocket, you can escape as slowly as you wish. That's not an efficient way to use a rocket, though.

Answer 7

How can you get up out of anything without starting out with some speed? The "escape velocity" is merely the minimum speed needed to have enough energy to get out.

A similar question would be: How come I can't get a car without having the money for the "purchase price"?

Answer 8

No. Lunar get away velocity is two.37 (km/sec) ~ 5300 mph Computed by: SQRT(2*G*MoonMass/MoonRadius) the place G is gravitational consistent. Or, by: SQRT(2*MoonGravityAcc*MoonRadius) SQRT(2*a million.622 m/s^2 * a million,737,000 m) = = 2373 (meters / 2d) = 5300 mph notice that on the lunar floor you're closer to the middle of gravity. the only-6th is sq.-rooted so it aspects in at >40% for the respond. added information: get away velocity is the value a bullet desires to be shot at to "coast" each and each of how up & out of orbit. you're able to be able to make the comparable stopover at a slower velocity yet ought to combat gravity each and each of how up. The get away velocity decreases with altitude.

Answer 9

u r asking this question because u dont know wut escape velocity means
escape velocity means:- the velocity AT THE SURFACE OF EARTH NOT AT THE LAST POINT OF THE ATMOSPHERE
the velocity which gives the body enough energy to escape the gravitational field of earth, and when the body reaches the last point of the atmosphere, it;s velocity equals to ZERO.

Answer 10

the gravitational force acting on a body on the earths surface is a function of the distance from the centre of the earth , hence this force has to be overcome by imparting velocity, so that it can leave the earths surface.

its like pulling a thing from someones hand, you need to pull harder to overcome the force that the person is applying