Basic mechanics (split from poles of an electromagnet question)

[DandelionTheory]

4 minutes ago, Ghideon said:

 You asked about forces that sums to zero. But for a system with internally moving parts momentum will be conserved. Rotation or linear does not matter. Would you like an explanation that contains momentum as well as forces? 

Let's tackle this with ideas first.

You're implying rotation and linear momentum cannot be transformed from one to the other? That's ridiculous.

[Ghideon]

9 minutes ago, DandelionTheory said:

You're implying rotation and linear momentum cannot be transformed from one to the other? That's ridiculous.

Where did I clam that? You can not make a system move linear by having internal rotation. That should intuitively be easy to see knowing some basic mechanics. It can also be verified using math. Are you claiming that a closed system can propel itself by having internally rotating parts, not interacting with something external?  

 

Movements due to interactions with external forces, masses etc is of course another thing. But you have not asked about that.

 

Edited February 7, 2020 by Ghideon

[DandelionTheory]

 

 

28 minutes ago, Ghideon said:

Where did I clam that

Quote

F=ma but in the other direction

What if things rotate?

28 minutes ago, Ghideon said:

You can not make a system move linear by having internal rotation.

Right, you would need a linear component to transfer momentum to, like circle E.

Like letting go of a mary go round.

Edited February 7, 2020 by DandelionTheory

[Ghideon]

 

15 minutes ago, DandelionTheory said:

What if things rotate?

Then there will be internal rotations in the system. 

Analogy: A car with an engine (spinning the cars wheels) will be able to move linearly along a road due to the interaction between car's rotating wheels and the road. A car in space, with no contact with ground, will not move, regardless of how many wheels there are, how they are oriented, or how fast they are spinning. The car will not be able to move its centre of mass. Period.

 

15 minutes ago, DandelionTheory said:

Right, you would need a linear component to transfer momentum to, like circle E.

You seem to argue in favour of a reaction-less drive. They do not exist according to mainstream science as far as I know so please provide supporting evidence.

Edited February 7, 2020 by Ghideon
spelling and grammar

[DandelionTheory]

15 minutes ago, Ghideon said:

Then there will be internal rotations in the system

If you were in space between the bucket ends of 2 water wheels, close enough to put your feet on, and ran up both of them with downward force only, you would pop up above them and they would spin in place. If you jumped but a tether attached to both wheels axis pulled you back, the opposite force would pull them to you. Just run up the wheels again.

[Ghideon]

4 minutes ago, DandelionTheory said:

If you were in space between the bucket ends of 2 water wheels, close enough to put your feet on, and ran up both of them with downward force only, you would pop up above them and they would spin in place. If you jumped but a tether attached to both wheels axis pulled you back, the opposite force would pull them to you. Just run up the wheels again.

The center of mass of the system will not move. The "system" in this case would be me and the other components mentioned. Momentum (linear and rotational) will be conserved. 

 

 

Edited February 8, 2020 by Ghideon

[DandelionTheory]

15 minutes ago, Ghideon said:

The center of mass of the system will not move. The "system" in this case would be me and the other components mentioned. Momentum (linear and rotational) will be conserved. 

 

 

So force applied to 2 wheels at 90° throws off their center of gravity?

You said that's impossible, survey says! "No"

So why can't you jump off a wheel by applying force at 90°?

Edited February 8, 2020 by DandelionTheory

[swansont]

!

Moderator Note

This has been split into a mainstream physics discussion. No speculation allowed.

 

[Ghideon]

5 hours ago, DandelionTheory said:

So force applied to 2 wheels at 90° throws off their center of gravity?

You said that's impossible, survey says! "No"

Maybe we can start from the basics of classical mechanics? Do you know what conservation of momentum is?

Do you accept it as a generally applicable principle? 

Can you make a picture and show the survey that contradicts me? That way we will clear up any misunderstandings.