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Newton's third law problem.
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IanB:

--- Quote from: electrodacus on November 24, 2022, 11:43:29 pm ---You did that yourself with your gif animation.

You had a 3:2 gear ratio
Showed a wheel traveling 3 squares and the other 2 squares while vehicle also moved one square.
I mentioned to fix one of the moving surfaces to represent the earth and your answer was

"With the fixed ground on the left the treadmill moves to the right one square. When this happens the vehicle moves two squares to the left."

I asked if you observe such a thing in reality meaning treadmill moves one square relative to ground while vehicle moves two squares also relative to ground.

I obviously got no answer from you.
--- End quote ---

It didn't deserve an answer. Of course it would do the same thing in reality. It is a model of reality.


--- Quote ---In the same way you can claim that with a 1:1 gear ratio the vehicle moves 2 squares while treadmill does not move at all.

--- End quote ---

Equally, of course you cannot claim this. Because no accurate model will predict such a thing.
IanB:

--- Quote from: electrodacus on November 24, 2022, 10:16:22 pm ---If it exceeds wind speed directly downwind or it drives at any speed directly upwind you know for sure energy storage is involved as else it can not work based on currently agreed laws of physics.
--- End quote ---

There are no "currently agreed" laws of physics that would claim this. You are the only person who says this. Every textbook, every physics professor, everyone in this forum, every qualified engineer in the world would disagree with you.

You keep making incorrect statements, such as suggesting that power has a direction like "left" or "right", "forwards" or "backwards", when everyone here has repeatedly told you that power is a scalar quantity, it has no direction.
electrodacus:

--- Quote from: IanB on November 25, 2022, 12:24:33 am ---
Equally, of course you cannot claim this. Because no accurate model will predict such a thing.

--- End quote ---

Your mathematical model will can predict almost anything with not many constraints.
And yes you can show your vehicle moving two squares relative to the grid and of course 2 squares on the fixed treadmill representing ground and also two squares on the non moving treadmill.
But if you insist in treadmill moving you can move it 1 square and vehicle can move any random value relative to ground.
 
The thing that your model is not considering is Newton's 3'rd law.
The gear is locked and treadmill applying a force to the generator wheel will not create a larger force at the motor wheel because that is physically possible without some other external force or force provided by stored energy.
Since there are no other external sources it is clear is energy storage. (Also demonstrated in my slow motion video).

I'm still not sure if is the wrong understanding of the difference between power and energy or the fact that any action has an equal and opposite reaction.

Power at the motor wheel will always be lower than power at the generator wheel meaning vehicle can not move against the direction of the treadmill powering the generator wheel.
Power out (at the motor wheel) will need to be larger than power extracted at the generator wheel in order for the vehicle to move against the treadmill direction and the only way to do that is to store energy then use that stored energy to power the motor wheel at any power you want (higher power for lower duration or lower power for longer duration but always more than generated at that time in order to be able to move in the other direction).

Why do none of you use the electric model ?  It should be harder to make mistakes for someone with electrical knowledge (at least I will think so).
But no matter if electrical or mechanical system the output power will always be lower unless you add energy storage and then for small portion of time you can output higher power by using stored energy.
electrodacus:

--- Quote from: IanB on November 25, 2022, 12:31:24 am ---
--- Quote from: electrodacus on November 24, 2022, 10:16:22 pm ---If it exceeds wind speed directly downwind or it drives at any speed directly upwind you know for sure energy storage is involved as else it can not work based on currently agreed laws of physics.
--- End quote ---

There are no "currently agreed" laws of physics that would claim this. You are the only person who says this. Every textbook, every physics professor, everyone in this forum, every qualified engineer in the world would disagree with you.

You keep making incorrect statements, such as suggesting that power has a direction like "left" or "right", "forwards" or "backwards", when everyone here has repeatedly told you that power is a scalar quantity, it has no direction.

--- End quote ---

Actually there are and law of conservation of energy is a law for a good reason.
Your output (propulsion) power can not be larger than input generated power.

I showed the wind power equation used by any engineer in the world that needs it and it shows that wind power available is highest when the wind speed is highest relative to vehicle and zero when there is no wind speed relative to vehicle.

So a vehicle can move against the wind direction only when output (propulsion power) is higher than input wind power.
Since that can not happen due to energy conservation law you need to use energy storage to move a vehicle upwind.

If you ever swimmed in a river against the current without being anchored to the ground you will have needed a minimum power just to maintain your position relative to the ground.
IanB:

--- Quote from: electrodacus on November 25, 2022, 12:53:56 am ---
--- Quote from: IanB on November 25, 2022, 12:24:33 am ---
Equally, of course you cannot claim this. Because no accurate model will predict such a thing.

--- End quote ---

Your mathematical model will can predict almost anything with not many constraints.
--- End quote ---

But the model does have constraints. It is constrained by an accurate representation of the system. What the model does, the real system does. And vice versa.


--- Quote ---And yes you can show your vehicle moving two squares relative to the grid and of course 2 squares on the fixed treadmill representing ground and also two squares on the non moving treadmill.
But if you insist in treadmill moving you can move it 1 square and vehicle can move any random value relative to ground.
--- End quote ---

And what's wrong with that?
 

--- Quote ---The thing that your model is not considering is Newton's 3'rd law.
--- End quote ---

Because it is not relevant.


--- Quote ---The gear is locked and treadmill applying a force to the generator wheel will not create a larger force at the motor wheel because that is physically possible without some other external force or force provided by stored energy.
--- End quote ---

This is demonstrably not true. If I have a 10:1 lever, I can apply a force of 1 N on the longer end and get a force of 10 N at the shorter end. Gears are no different from levers. Even if the wind exerts a force of 1 N on the vehicle, we can use gearing to make the motor exert a force of 10 N at the wheels in the opposite direction.


--- Quote ---Since there are no other external sources it is clear is energy storage. (Also demonstrated in my slow motion video).
--- End quote ---

Clearly not true, as above.


--- Quote ---I'm still not sure if is the wrong understanding of the difference between power and energy or the fact that any action has an equal and opposite reaction.
--- End quote ---

Everyone has been asking you to look inside yourself for the wrong understanding, but you won't do it.


--- Quote ---Power at the motor wheel will always be lower than power at the generator wheel
--- End quote ---

True


--- Quote ---meaning vehicle can not move against the direction of the treadmill powering the generator wheel.
--- End quote ---

Not true. Any small amount of power at the motor wheel can move the vehicle with appropriate gearing.


--- Quote ---Power out (at the motor wheel) will need to be larger than power extracted at the generator wheel in order for the vehicle to move against the treadmill direction and the only way to do that is to store energy then use that stored energy to power the motor wheel at any power you want (higher power for lower duration or lower power for longer duration but always more than generated at that time in order to be able to move in the other direction).
--- End quote ---

Not true. See above.


--- Quote ---Why do none of you use the electric model ?  It should be harder to make mistakes for someone with electrical knowledge (at least I will think so).
But no matter if electrical or mechanical system the output power will always be lower unless you add energy storage and then for small portion of time you can output higher power by using stored energy.

--- End quote ---

The electrical model is even easier. As long as there is some small power at the electric motor the vehicle can move. The stronger the wind, the more power, so the easier it is for the vehicle to move.


--- Quote from: electrodacus on November 25, 2022, 01:03:28 am ---
--- Quote from: IanB on November 25, 2022, 12:31:24 am ---
--- Quote from: electrodacus on November 24, 2022, 10:16:22 pm ---If it exceeds wind speed directly downwind or it drives at any speed directly upwind you know for sure energy storage is involved as else it can not work based on currently agreed laws of physics.
--- End quote ---

There are no "currently agreed" laws of physics that would claim this. You are the only person who says this. Every textbook, every physics professor, everyone in this forum, every qualified engineer in the world would disagree with you.

You keep making incorrect statements, such as suggesting that power has a direction like "left" or "right", "forwards" or "backwards", when everyone here has repeatedly told you that power is a scalar quantity, it has no direction.

--- End quote ---

Actually there are and law of conservation of energy is a law for a good reason.
--- End quote ---

Conservation of energy is not a useful analysis here.


--- Quote ---Your output (propulsion) power can not be larger than input generated power.
--- End quote ---

True, but irrelevant.


--- Quote ---I showed the wind power equation used by any engineer in the world that needs it and it shows that wind power available is highest when the wind speed is highest relative to vehicle and zero when there is no wind speed relative to vehicle.
--- End quote ---

As has previously been explained by many people, it is the wind speed relative to the ground that decides how much power can be extracted by the vehicle, not the speed relative to the vehicle. If you take an equation and apply it incorrectly, you will draw incorrect conclusions.


--- Quote ---So a vehicle can move against the wind direction only when output (propulsion power) is higher than input wind power.
--- End quote ---

As repeated many times, not true.


--- Quote ---Since that can not happen due to energy conservation law you need to use energy storage to move a vehicle upwind.
--- End quote ---

Nonsense.


--- Quote ---If you ever swimmed in a river against the current without being anchored to the ground you will have needed a minimum power just to maintain your position relative to the ground.

--- End quote ---

Yes, but the vehicle is anchored to the ground. It has wheels with friction in contact with the ground. So the swimming analogy does not apply. The swimming analogy would only apply to a free floating airship above the ground (a body which would be "swimming" in the air).
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