Terminal Velocity of Objects Falling into the Sun

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    Falling Sun The sun
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Discussion Overview

The discussion revolves around the terminal velocity of objects falling into the Sun, exploring the relationship between gravitational acceleration, escape velocity, and the speed of light. Participants engage in calculations and assumptions regarding the conditions of the fall, including the distance from which the object is dropped.

Discussion Character

  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants assert that an object falling into the Sun would not reach the speed of light, suggesting an impact speed of about 600 km/s.
  • There is a contention about the necessity of knowing the distance from which the object is falling to provide a terminal velocity value.
  • One participant presents a calculation for gravitational acceleration using the formula A = GM/r^2, but others point out that acceleration does not equate to velocity and question the accuracy of the numbers used.
  • Another participant suggests that the calculation is intended to find the gravitational acceleration at the Sun's surface, which they claim is approximately 300 m/s².
  • Some participants mention the concept of escape velocity and propose that if an object is dropped from infinity, it could be considered in terms of escape velocity.

Areas of Agreement / Disagreement

Participants generally disagree on the calculations and interpretations of gravitational acceleration versus terminal velocity, with no consensus reached on the final speed of an object falling into the Sun.

Contextual Notes

There are unresolved assumptions regarding the distance of the fall and the definitions of escape velocity versus terminal velocity. The discussion includes various calculations that may depend on specific conditions not fully articulated by participants.

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Does an object falling into the sun reach approximately the speed of light?
 
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Not even close. It would impact at about 600 km/s.
 
Not even close.

[ EDIT You're fast! ]
 
Vanadium 50 said:
Not even close. It would impact at about 600 km/s.

Don't you have to know from how far it's falling to provide a value?
 
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DaveC426913 said:
Don't you have to know from how far it's falling to provide a value?
No, assume infinity and look up the escape velocity.
 
What about this calc

A= GM/r^2

A= 10^-11 10^30 / 10^12
= 10^7

That's pretty fast, does this not apply?
 
Acceleration is not velocity. And your calculation has wrong numbers in it.
 
God Plays Dice said:
What about this calc

A= GM/r^2

A= 10^-11 10^30 / 10^12
= 10^7

That's pretty fast, does this not apply?
You are trying to calculate the gravitational acceleration on the "surface" of the Sun.
If you do it correctly you will get about 300 m/s^2.

But this is not a speed anyway. You cannot compare this with the speed of light (or any speed).
 
nasu said:
You are trying to calculate the gravitational acceleration on the "surface" of the Sun.
If you do it correctly you will get about 300 m/s^2.

But this is not a speed anyway. You cannot compare this with the speed of light (or any speed).
https://en.wikipedia.org/wiki/Sun
I think it's the escape velocity. If you put it infinitely. I'm no physicist, just using logic.
Vanadium is right
 
  • #10
DaveC426913 said:
Don't you have to know from how far it's falling to provide a value?
I think if you drop it infinitely, it's the escape velocity.
 
  • #11
Stephanus said:
https://en.wikipedia.org/wiki/Sun
I think it's the escape velocity. If you put it infinitely. I'm no physicist, just using logic.
Vanadium is right
No, that formula is an acceleration and not a velocity.
I did not say anything about Vanadium's post.
 
  • #12
Stephanus said:
I think if you drop it infinitely, it's the escape velocity.
Yes, I was about to follow up with the assumption that it falls from infinity.
Even if it doesn't, that still acts as the upper limit of final velocity.
 

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