- #1

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what is the energy needed to move an object away from the planets gravitational field at CONSTANT speed?

1) Ep

2)Ek

3)Change in Ep

4)Change in Ek

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- Thread starter sundeepsingh
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In summary: The relevance of constant speed is that it means the change in kinetic energy is zero. Suppose the object was moving at escape velocity to begin with. If the problem did not say the object moved with constsant speed you would not have to add any energy to get the object to infinity, but the speed of the object there would be zero. Adding the requirement of constant speed means the object is still moving with escape velocity at infinity, so that you still must add an amount of energy equal to the change in potential energy.Refer to my explanation , the answer is worth 5 minutes , should not take 30 minutes.

- #1

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what is the energy needed to move an object away from the planets gravitational field at CONSTANT speed?

1) Ep

2)Ek

3)Change in Ep

4)Change in Ek

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- #2

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How about showing some work, i.e. relevant equations.

This seems to be a homework problem.

This seems to be a homework problem.

- #3

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I have always wonder how escape velocity is defined - I thought gravity had infinite 'reach'?

- #4

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The escape velocity is the velocity at which the object has sufficient kinetic energy so that its total energy (kinetic plus potential) is 0. That way, without any other force (i.e.

I don't understand the "constant speed" part. If you can set up the forces (rocket or whatever) so that the object moves with constant velocity, then it

- #5

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During the launch of the object , it is believed to have the potential energy due to gravitation field of the planet and the needed kinetic energy , then after it takes off , and eneters the space , it is assumed to travel far off and then sail in space (with negligible velocity) where the potential energy is taken to be zero.From here we calculate the escape velocity .

So it is basically the process in which Earth's potential energy is being lost to gain the required 'v' which is the escape velocity , to overcome the Earth's gravitational pull and sail off.

I would go with option (3)

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- #7

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- #8

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Refer to my explanation , the answer is worth 5 minutes , should not take 30 minutes.

BJ

BJ

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- #11

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Refer to LeonhardEuler's explanation (#7) , the answer is worth 5 seconds , should not take 5 minutes.Dr.Brain said:Refer to my explanation , the answer is worth 5 minutes , should not take 30 minutes.

BJ

Oh, and by the way, your explanation does not solve

Last edited:

- #12

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The answer to your question will still remain the (3) option , even if we were not concerned about the CONSTANT VELOCITY thing , because the basic process remains the same , the process is basically an energy-change process.

BJ

Escape velocity constant is a physical constant that represents the minimum velocity needed for an object to escape the gravitational pull of a celestial body, such as a planet or moon.

The value of escape velocity constant is approximately 11.2 kilometers per second, or 6.95 miles per second.

Escape velocity constant is calculated using the equation v = √(2GM/R), where v is the escape velocity, G is the gravitational constant, M is the mass of the celestial body, and R is the distance from the center of the body.

Yes, the value of escape velocity constant varies depending on the mass and size of the celestial body. For example, the escape velocity of the moon is much lower than that of Earth due to its smaller size and mass.

Escape velocity constant is important in space exploration as it determines the minimum velocity needed for a spacecraft to break away from a celestial body's gravitational pull. It also helps in understanding the formation and structure of celestial bodies.

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