[Kryptid]

Kryptid,
No, there is only one momentum, angular momentum.
The linear momentum is angular momentum!!!!
The linear momentum is angular momentum that has infinite radius, the axis of rotation is infinitely far away,
Jano

The Department of Physics website I linked stated:

The two conservation laws- linear and angular momentum- are absolutely separate. Neither one can be converted to the other.

Kryptid,
you do not trust me?
Here: https://www.khanacademy.org/science/ap-physics-1/ap-torque-angular-momentum/conservation-of-angular-momentum-ap/v/ball-hits-rod-angular-momentum-example

Jano

That website does not support your position that linear momentum is angular momentum. All it shows is that a moving ball can have angular momentum even if it isn't rotating. The moving ball transferred both its linear momentum and its angular momentum to the rod.

The link you posted actually demonstrates clearly that linear and angular momentum are different. In the scenario where the ball hits the rod, it causes the rod to rotate and thus shows that the ball possessed angular momentum in that situation. When the ball hits the axis instead, however, there is no rotation. The ball had no angular momentum in that case. In both cases, the ball was moving at the same velocity and therefore had the same linear momentum. So angular momentum can obviously vary independently of linear momentum.

This is not new theory, this is physics!
Jano

Physics states that linear momentum and angular momentum are different. Again, refer back to the Department of Physics website I linked.

[Jaaanosik (OP)]

...

Are you sure the linear momentum cannot be converted to angular momentum?

Yes. See the link above.

Where is the conservation of energy broken here?

It isn't. Conservation of momentum is what is broken.

Kryptid,
where do we go from here after you watched the linked video?
Do see how the linear momentum can be converted to the angular momentum?
Jano

[Kryptid]

Do see how the linear momentum can be converted to the angular momentum?

You can't do that any more than you can convert mass to electric charge.

In that picture you posted, both the angular and linear momentum of the ball are transferred to the rod. It's not a case of linear momentum being turned into angular momentum.

[Jaaanosik (OP)]

Kryptid,
Please, look here again:



Is there an angular momentum in that figure?
Jano

[Kryptid]

Is there an angular momentum in that figure?

Yes. Objects don't have to be spinning to have angular momentum. Your link already explained how a non-spinning object can have angular momentum.

[Jaaanosik (OP)]

Is there an angular momentum in that figure?

Yes. Objects don't have to be spinning to have angular momentum. Your link already explained how a non-spinning object can have angular momentum.

Great,
From a textbook: MATHEMATICAL METHODS FOR PHYSICISTS, 6th edition by George B. Arfken and Hans J. Weber




I can show that the equation 5.124 is not correct equation even if we consider the string to be "mass-less".
Do you trust my claim?
Jano

[Kryptid]

I can show that the equation 5.124 is not correct equation even if we consider the string to be "mass-less".
Do you trust my claim?
Jano

I'm not going to trust anyone's claim that modern physics is wrong unless they can provide compelling evidence for it.

[Jaaanosik (OP)]

I can show that the equation 5.124 is not correct equation even if we consider the string to be "mass-less".
Do you trust my claim?
Jano

I'm not going to trust anyone's claim that modern physics is wrong unless they can provide compelling evidence for it.

Kryptid,
what do think about this?





The equation Eq. 23 is correct equation for a pendulum with a bob that does rotate when it falls down. The equation Eq. 23 is more complex than Eq. 22 and it shows that Eq. 23 tangential velocity will be less than Eq. 22 tangential velocity. The smaller tangential velocity leads to smaller tangential and centripetal accelerations.

Jano

[Kryptid]

To be honest, I'm not familiar with either equation. What are they even calculating? I don't see anywhere that it is stated that it is calculating either angular momentum or linear momentum.

[Jaaanosik (OP)]

To be honest, I'm not familiar with either equation. What are they even calculating? I don't see anywhere that it is stated that it is calculating either angular momentum or linear momentum.

Kryptid,
I am sure you know
If we know rotational energy/angular velocity of a body we can determine angular momentum.

Are you going to claim you did not know it?

Here goes the comparison to the video.
We change the rod for the pendulum.
If we change the original potential energy in the pendulum textbook example for the kinetic energy of the ball in the video then we have pretty much the same scenario and the analysis holds.
Do you understand what I said or I need to draw it?

The rotational energy has two components, I hope you see that.
It follows that the pendulum bob design plays very important role in determination of the velocity.
Do you agree?

The important question is if the the same original momentum mv can generate two different angular momentums.
Do you see why I am asking this question?

Jano

[Kryptid]

Are you going to claim you did not know it?

I'm sure I knew that back when I was still in school, but it's been so long since I was exposed to that equation that I forgot about it.

It follows that the pendulum bob design plays very important role in determination of the velocity.
Do you agree?

Yes, the pendulum design does affect the pendulum velocity.

The important question is if the the same original momentum mv can generate two different angular momentums.

Mass times velocity alone can't generate any angular momentum, because it is a measure of linear momentum. Angular momentum requires a radius of rotation. If there is no radius of rotation, then there is no angular momentum.

Do you see why I am asking this question?

Nope.

Not that this matters anyway, as your spaceship design doesn't have any net angular momentum to begin with. The two balls spin in opposite directions, so the net angular momentum is zero. So even if it was possible to convert angular momentum into linear momentum, your ship still could not go anywhere because zero net angular momentum could not produce non-zero net linear momentum.

[Jaaanosik (OP)]

Kryptid,



The symmetrical wheel has its axle attached to the spaceship.
When the ball hits the arm of the symmetrical wheel attached to the spaceship it will not take anything from the spaceship forward momentum.
The forward spaceship momentum will be unchanged.
The symmetrical wheel will start to rotate.
Do you agree?
Jano

[Kryptid]

Do you agree?

Nope. The wheel will start to rotate, but it will also transmit linear momentum from the ball to the ship. If you want to eliminate that, you would need to have another ball coming from the opposite direction hitting the other arm.

[Jaaanosik (OP)]

Do you agree?

Nope. The wheel will start to rotate, but it will also transmit linear momentum from the ball to the ship. If you want to eliminate that, you would need to have another ball coming from the opposite direction hitting the other arm.

Kryptid,
you should have said the rotation of the wheel is going to have a torque and this torque will rotate the spaceship.
I'd say the second wheel on the same axle with the opposite rotation caused by the ball on the other side will cancel the first wheel torque.

If you remember the arm from the video, the inertia of the arm, centrifugal force would be pulling the spaceship back, but here the wheel is symmetrical on purpose.
Every point on the wheel has a symmetrical point across the axis of rotation and the only result is a torque.
When the torques are cancelled out then there is no force pulling the spaceship backwards or rotating it.
Jano

[Kryptid]

When the torques are cancelled out then there is no force pulling the spaceship backwards or rotating it.

Yes there is. For the reason I just stated in my last post. Conservation of linear momentum won't allow it to disappear into nothingness (nor can it be converted into angular momentum. Remember this? https://van.physics.illinois.edu/qa/listing.php?id=24173&t=is-linear-momentum-converted-to-angular-momentum).

[Jaaanosik (OP)]

When the torques are cancelled out then there is no force pulling the spaceship backwards or rotating it.

Yes there is. For the reason I just stated in my last post. Conservation of linear momentum won't allow it to disappear into nothingness (nor can it be converted into angular momentum. Remember this? https://van.physics.illinois.edu/qa/listing.php?id=24173&t=is-linear-momentum-converted-to-angular-momentum).

Kryptid,
Please, go ahead, do an experiment as shown in the linked video.

Are you saying that the water mills should not work? They are miracles?
Jano

[Kryptid]

Kryptid,
Please, go ahead, do an experiment as shown in the linked video.

Are you saying that the water mills should not work? They are miracles?
Jano

I don't see a link.

[Jaaanosik (OP)]

Kryptid,
Please, go ahead, do an experiment as shown in the linked video.

Are you saying that the water mills should not work? They are miracles?
Jano

I don't see a link.

Kryptid,
post #80

https://www.khanacademy.org/science/ap-physics-1/ap-torque-angular-momentum/conservation-of-angular-momentum-ap/v/ball-hits-rod-angular-momentum-example

The explanation to your confusion is around the 3rd minute.
Do you really think the water mills are miracles?
Jano

[Kryptid]

The explanation to your confusion is around the 3rd minute.

I don't have any confusion.

Do you really think the water mills are miracles?

No. Water mills are attached to buildings which, in turn, are attached to the ground. The linear momentum they receive from the falling water is transmitted to the entire planet. Since the Earth is so incredibly massive, you don't notice its change in momentum.

[Jaaanosik (OP)]

The explanation to your confusion is around the 3rd minute.

I don't have any confusion.

Do you really think the water mills are miracles?

No. Water mills are attached to buildings which, in turn, are attached to the ground. The linear momentum they receive from the falling water is transmitted to the entire planet. Since the Earth is so incredibly massive, you don't notice its change in momentum.

Kryptid,
what happens when two torques of the opposite rotations of two wheels cancel out?
Jano

Edit:
to help you: https://en.wikipedia.org/wiki/Control_moment_gyroscope