Can a Vacuum in Space Create Drag on Moving Objects?

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SUMMARY

The discussion centers on the misconception that a vacuum in space can create drag on moving objects. Participants clarify that a vacuum does not interact with objects in a way that produces drag, as interactions are governed by Newton's laws of motion. Specifically, when a rocket expels exhaust gases, it generates thrust through the equal and opposite reaction of the gases, not through any resistance from the vacuum. The concept of resistance in this context is misapplied, as forces act on different bodies and do not cancel each other out.

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  • Awareness of the properties of a vacuum
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  • #61
im not talking about here on Earth I am talking about in a perfect weightless vacuum...

: If there were no gravity, and if the air did not impede the motion of bodies, then anybody will continue its given motion with uniform velocity in a straight line.
: Every body under the sole action of its innate force moves uniformly in a straight line indefinitely unless something extraneous hinders it.
: Every body perseveres in its state of being at rest or of moving uniformly straight forward except insofar as it is compelled to change its state by forces impressed.

what is an impressed force...This force consists in the action only, and remains no longer in the body when the action is over. For a body maintains every new state it acquires by its inertia only. But impressed forces are of different origins, as from percussion, from pressure, from centripetal force.

impressed forces are of different origins, as from percussion, from pressure, from centripetal force.

so me throwing anything in space vacuum would result in the impressed forces from pressure of my arm and equal and opposite force applied to the object and both the object and me will move away from each other and then back toward each other simultaneously...canceling each others impressed forces so no movement will occur
 
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  • #62
Newtonforce said:
so me throwing anything in space vacuum would result in the impressed forces from pressure of my arm and equal and opposite force applied to the object and both the object and me will move away from each other and then back toward each other simultaneously...canceling each others impressed forces so no movement will occur

So what is your response to my scenarios with the ball and the slingshot above?
 
  • #63
imstill finding my feet ...but its definatley probable that rockets cannot propell them selves in a space vacuum...by recoil alone...force impressed on rocket chamber are simultaneously moving against and away from rocket chamber... The reciprocal of 0 force is 0 force. The equal and opposite reaction to 0 would be 0.
 
  • #64
Newtonforce said:
im not talking about here on Earth I am talking about in a perfect weightless vacuum..
OK.

Newtonforce said:
: If there were no gravity, and if the air did not impede the motion of bodies, then anybody will continue its given motion with uniform velocity in a straight line.
: Every body under the sole action of its innate force moves uniformly in a straight line indefinitely unless something extraneous hinders it.
: Every body perseveres in its state of being at rest or of moving uniformly straight forward except insofar as it is compelled to change its state by forces impressed.
OK.

Newtonforce said:
what is an impressed force...This force consists in the action only, and remains no longer in the body when the action is over.
"impressed" force is just any external force acting on an object. And yes, as soon as you remove it, it no longer acts on the body.

Newtonforce said:
so me throwing anything in space vacuum would result in the impressed forces from pressure of my arm and equal and opposite force applied to the object and both the object and me will move away from each other
You throwing your shoe in space would have you exerting a force on the shoe and the shoe exerting a force on you. You both accelerate and move away from each other. As soon as you break contact you no longer exert forces on each other, you just keep on moving at constant velocity.

Newtonforce said:
and then back toward each other simultaneously.
Why is that?
 
  • #65
Newtonforce said:
The reciprocal of 0 force is 0 force. The equal and opposite reaction to 0 would be 0.
Why do you keep repeating this strange mantra?

I could just as easily say: The equal and opposite reaction to 10 N of force is 10 N of force. So?
 
  • #66
stored energy in the rubber will move the ball as far as the rubber band will recoil ...what has been impressed onto the ball that the ball did not impress back to the rubberband
The reciprocal of 0 force is 0 force. The equal and opposite reaction to 0 would be 0.
 
  • #67
Newtonforce said:
but its definatley probable that rockets cannot propell them selves in a space vacuum
Seriously?
 
  • #68
.force impressed on rocket chamber are simultaneously moving against and away from rocket chamber...
 
  • #69
Newtonforce said:
stored energy in the rubber will move the ball as far as the rubber band will recoil ...what has been impressed onto the ball that the ball did not impress back to the rubberband
The reciprocal of 0 force is 0 force. The equal and opposite reaction to 0 would be 0.

So you're pulling the rubber band back, the pebble along with it. You let go of the rubber band and it propels itself and the pebble forward. The rubber band eventually stretches forward to a point where it cannot go further forward. This is what happens on Earth and in space.

But now you say that things start to differ at this point. You're saying that now the pebble will stick to the rubber band in space and go no further than the rubber band while on Earth the pebble will detach itself form the rubber band and keep moving forward. Correct?

The reason I am doing this is to illustrate (hopefully to you!) that there are some seriously bizarre consequences that come from your model.
 
  • #70
how can motion be achieved by a balanced equation...there has to be a differential between the interior and the exterior...
 
  • #71
Again and again, you still don't understand Newton's 3rd law. There is nothing more to say.
 
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  • #73
I think this thread has run its course. @Newtonforce: Please read up on Newton's 3rd law.
 
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