- #1

- 16

- 0

What is the terminal velocity of a mass that falls from the edge of earth's gravity well to earth's surface?

Thank you in advance for your answer.

Peace

rwj

You are using an out of date browser. It may not display this or other websites correctly.

You should upgrade or use an alternative browser.

You should upgrade or use an alternative browser.

- Thread starter rwjefferson
- Start date

- #1

- 16

- 0

What is the terminal velocity of a mass that falls from the edge of earth's gravity well to earth's surface?

Thank you in advance for your answer.

Peace

rwj

- #2

Hootenanny

Staff Emeritus

Science Advisor

Gold Member

- 9,621

- 6

Terminal velocity by definition requires that there be a drag force. Therefore, no drag force - no terminal velocity.

What is the terminal velocity of a mass that falls from the edge of earth's gravity well to earth's surface?

Thank you in advance for your answer.

Peace

rwj

- #3

arildno

Science Advisor

Homework Helper

Gold Member

Dearly Missed

- 9,970

- 134

What do you mean by "the edge of earth's gravity"??

What is the terminal velocity of a mass that falls from the edge of earth's gravity well to earth's surface?

Thank you in advance for your answer.

Peace

rwj

As modelled by classical Newtonian mechanics, the "edge" where there is zero influence from Earth's gravity must be placed infinitely far away from the Earth.

If we imagine a a particle starting at rest at infinity, and then is solely influenced by earth's gravity, then it will hit Earth with the velocity known as "escape velocity".

Perhaps you might call this a "terminal velocity", but that would be an abuse of terms, as Hootenanny has told you already.

- #4

- 16

- 0

What do you mean by "the edge of earth's gravity"??

If we imagine a a particle starting at rest at infinity, and then is solely influenced by earth's gravity, then it will hit Earth with the velocity known as "escape velocity".

Perhaps you might call this a "terminal velocity", but that would be an abuse of terms, as Hootenanny has told you already.

A plot of gravitational potential of the earth generates a hyperbolic cross section. The sudden dip in the center is the origin of the name 'gravity well'. The 'edge' of that well occurs where minimal perpendicular velocity counters the force of gravity. I agree that the 'edge' of that well is as arbitrary as 'minimal perpendicular velocity'.

I commend you on your insight.

I will predict that a free-falling mass will reach maximum velocity of 40,200 km/h as it hits the surface of the earth.

Thanks

rwj

- #5

Hootenanny

Staff Emeritus

Science Advisor

Gold Member

- 9,621

- 6

I'd have to disagree with you there. Your calculations are incorrect.I will predict that a free-falling mass will reach maximum velocity of 40,200 km/h as it hits the surface of the earth.

Thanks

rwj

- #6

- 16

- 0

I'd have to disagree with you there. Your calculations are incorrect.

What, may I ask, are your better reasons and and calculations that I should doubt equal to escape velocity?

Peace

rwj

- #7

Hootenanny

Staff Emeritus

Science Advisor

Gold Member

- 9,621

- 6

Whoops! I beg your pardon, I thought you had 40 000 km/What, may I ask, are your better reasons and and calculations that I should doubt equal to escape velocity?

Peace

rwj

You are indeed correct, the escape velocity from earth is indeed approximately 40 000 km/

Apologies for the mix-up!

- #8

- 144

- 3

What is the terminal velocity of a mass that falls from the edge of earth's gravity well to earth's surface?

Thank you in advance for your answer.

Peace

rwj

It would probably be best that you specified either an object's starting distance from the Earth's surface or a point beginning at a given rate of acceleration m/s^2, as in theory, the further an object is placed from the Earth (and still capable of accelerating towards it), the more time it is given to accelerate and gain a higher end velocity especially considering your "no atmosphere", "no friction", "no extraneous factors" clause.

Share:

- Replies
- 17

- Views
- 5K