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Split Thread The validity of classical physics (split from: DWFTTW)

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humber said:
...and therefore, the skater can only reach windspeed if the coefficient of drag is zero, or the balloon can generate more power than is available.
The force on the skater at maximum velocity, will never be zero.
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There is always the limiting case where the maximum velocity is zero.
 
mender said:
No error. Power = force * velocity difference. Balloon speed to wind difference drops by the same amount that the skater speed to ground increases.
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The force of the wind on the balloon decreases with velocity, as shown by the equation.

The equation balances and the skater goes faster than the wind. Even you should be able to see both sides of the equation.
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The drag force of the skater increases with square of the velocity, as shown by the equation.

The drag force will exceed the driving force, before windspeed.
The drag power will exceed the driving power, before windspeed.
 
...and therefore, the skater can only reach windspeed if the coefficient of drag is zero, or the balloon can generate more power than is available.
The force on the skater at maximum velocity, will never be zero.
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AND the balloon would have to reach windspeed....
 
recursive prophet said:
@Dan_O-Thanks for the reply. Seems whenever I get ready to ask a question things veer off in another direction. Still wish someone would address the continuity issue though. :confused:
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Are you talking about continuity of the wind or continuity of the wheel contact with the road? Humber addressed both of those in the original thread. I'd have to go back and look up the answer to get it right. The wind part is cleverly avoided by the treadmill because there is no wind. Eliminating the wheel contact however would be a problem but there are ways around that. Suffice it to say, there are hidden forces at work.
 
How embarassing for you, humber. You can't even do this simple problem.

humber said:
The force of the wind on the balloon decreases with velocity, as shown by the equation.
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The force on the balloon is drag. That changes as the square of the velocity change. The balloon speed vs the wind speed increases when the balloon is slowed down, so the power goes up as the square of the change as shown by the equation.

Now add the part that you got right:

humber said:
The drag force of the skater increases with square of the velocity, as shown by the equation.
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And maybe (just maybe) you'll see that the gears don't need to add power to change the speeds. The power is still balanced; the balloon is now going half the speed that it was before and the skater is going twice the speed that she was before.

By the way, you'd better go back and fix your graph. You got the balloon power wrong using your own equation. The way it is now is saying that the balloon won't be able to move in a wind unless it is already moving - which is not surprising given most of your arguments.
 
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mender said:
How embarassing for you, humber. You can't even do this simple problem.
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I'll hide my embarrassment behind my fan.

The force on the balloon is drag. That increases as the square of the velocity change. The balloon speed vs the wind speed increases when the balloon is slowed down.
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No. the force of the wind is due to drag. In the case of the balloon, that decreases with the square of the difference between wind and balloon. It falls as the balloon gains velocity. That is in the equation.

Now add the part that you got right:
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Big it up.

And maybe (just maybe) you'll see that the gears don't need to add power to change the speeds. The power is still balanced; the balloon is now going half the speed that it was before and the skater is going twice the speed that she was before.
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Totally misconstrued. The gears cannot change the power. If you do as you suggest, you may change the rate of acceleration to take advantage of the fact that the balloon is producing more force than the drag, at some lower speed, but that will stop when the balance occurs, as the equations prove.
Gears will not change the terminal velocity.
 
Dan O. said:
Yes, if the treadmill is off there is no motion.
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When there is no motion, and no wind, there is no power.

Anyway, you have posted a list of so-called wrong statements, so I think I am justified in asking you to defend them. Otherwise, remove them.

ETA:
You may chose.
 
All I can say is, humber, read it again, but more slowly this time, taking notes if you have to.
 
Dan O. said:
I posted a list of argument. Why don't you attack one of those.
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Hey, I was just wanting to toss a few insults at humber! How should I respond when I post:

"The force on the balloon is drag."

And humber replies:

"No. the force of the wind is due to drag." And he's also talking about the balloon!
 
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mender said:
All I can say is, humber, read it again, but more slowly this time, taking notes if you have to.
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I read it. It is not correct. Please provide the equations that you say should apply.

ETA:
Toss away. Don't mind me.
 
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