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# 514void

Senior Members

91

1. ## gravity stacking

umm, like at sea level or something?
2. ## gravity stacking

would something as massive as the earth fall at g or 2g towards the earth?
3. ## Angular momentum and linear momentum relationship

I would of thought that an objects angular momentum would be around an axis that went through the center of mass of the object. So when you say that angular momentum is conserved, you mean that both objects center of mass has angular momentum around the axis of the center of mass of both objects? and this is conserved? what about each objects angular momentum, is this considered in the calculation?
4. ## Angular momentum and linear momentum relationship

O, i'm just concerned with 2 objects, so do i pick a frame where the net momentum is 0? let us start out that both have 0 angular momentum. So any collision of the 2 objects will mean that each will have the exact opposite angular momentum as the other? (both objects have the same mass)
5. ## Angular momentum and linear momentum relationship

pick a point? for each object?
6. ## Angular momentum and linear momentum relationship

Ok, seems a bit strange if the rod is hit by the ball right on the front of the ball, I would of thought it would bounce straight back from where it came from without spinning, even if it hits the rod in the middle or near the end.
7. ## Angular momentum and linear momentum relationship

What happens if one of the objects gains angular momentum from the collision, like if a ball hits a rod near the end.
8. ## Angular momentum and linear momentum relationship

Is there loss of linear momentum of 2 objects in an elastic collision if the net angular momentum increases and vica versa?
9. ## Does a spinning disk gain relativistic mass

but yes, there would be a velocity gain as a linear function of the radius regardless of relativistic mass direction. Relativistic mass increases exponentially with velocity. So it would be beneficial to have the rest mass mostly near the edge of the disks. Is there anything else I should consider?
10. ## Does a spinning disk gain relativistic mass

I'm not so sure what happens. But I think that there is a warning against considering a change in any sort of structure of the object due to relativistic mass.
11. ## Does a spinning disk gain relativistic mass

Ok, That makes me think that if relativistic mass is directional, then there would be no relativistic mass force on the center of the disk when it isn't accelerating. this sort of makes sense since if relativistic mass isn't directional, then a spinning disk would slow down and eventually stop spinning. If relativistic mass is directional, then is slowing an object easier than speeding it?
12. ## Does a spinning disk gain relativistic mass

this is only true in only one reference frame. the reference frame would be spinning around the center of the disk, at the same angular velocity of the disk. spinning reference frames are sort of silly, since if the frame extends past a certain radius, it would be going FTL. Unless you propose some sort of spiral reference frame that has angular velocity that goes at the speed of light at infinity radius. This sounds sort of cool.
13. ## Does a spinning disk gain relativistic mass

relative velocity of what?
14. ## Does a spinning disk gain relativistic mass

unresolved as its isn't a clearly defined equation, so I could use it inappropriately.
15. ## Does a spinning disk gain relativistic mass

I had a look for it: http://en.wikipedia.org/wiki/Center_of_mass_(relativistic) It seem like it is unresolved.
16. ## Does a spinning disk gain relativistic mass

is newtonian mechanics and SR consistent with each other? If not, then is conservation of momentum only applicable to newtonian mechanics?
17. ## Does a spinning disk gain relativistic mass

so if I did relativistic maths, it would say that spinning up disks would keep their velocity, but if I did conservation of momentum maths it would say that it would slow down. (velocity as opposed to angular velocity) I'm not sure what maths I should do.
18. ## Does a spinning disk gain relativistic mass

wait, 1 person says it slows down and 1 person says it doesn't
19. ## Does a spinning disk gain relativistic mass

yer, it might take me awhile to figure it out, like how a disk can conserve its momentum in all frames with just spinning it since it gains relativistic mass.
20. ## Does a spinning disk gain relativistic mass

Nice analysis of the maths. I suppose I didn't apply the Hamiltonian and whatever else that doesn't apply to it like you probably would.
21. ## Does a spinning disk gain relativistic mass

Just apply it? Is that how physics works, apply the maths and make up random forces to fit the equations? And then find an analogy and strawman it? I don't think I can do that, its just so dishonest. But I will try and do the maths.... ok, lets assume the the container is 100 meters high. and lets say 10 meters wide. and weighs 1000kg. the disks are 8 meters in diameter. and they weigh 100kg each the motors weigh 10kg each component A: disk 1 and 2 are attached to a motor that can spin them in opposite directions. component B: disk 3 and 4 are attached to a motor that can spin them in opposite directions. the motors can slow down the disks and retrieve the energy component A and component B move up and down in opposite directions at 10 meters a second. they change directions at the top and bottom of the container, and the force to change their directions is applied at a constant rate when the centers of them between 20 meters and 10 meters away from the ends. when the center of a component is 20 meters from the top and travels to 20 meters from the bottom, the spins that the disks have will be slowed to a stop by a constant torque from its motor. when the center of a component is 20 meters from the bottom and travels to 20 meters from the top, the disks will be spun up by a constant torque from the motor. the component at the top will have twice as much mass as the component on the bottom because of the extra relativistic mass. ok, so each components rest mass is 210kg and the when it is at the top its mass is 420kg the force required to change the 210kg component is umm....... it arrives at 10 m/s going downwards and ends up going 10 m/s going upwards. so the force on the container is umm.... 210 / 1000 * 20 m/s... 4.2 m/s downwards. the upwards component is the same but upwards and double the mass so it is 420 / 1000 * 20 m/s... 8.4 m/s upwards. the difference is 4.2 m/s upwards. the actual difference would be less because the forces on the components would need to adjust for this acceleration, but lets keep it simple for the moment. the disks would need to spin very fast to get such a mass gain, and the shape of the disks would work better if the mass was concentrated near the rim. ok, there is some maths, I hope its right.
22. ## Does a spinning disk gain relativistic mass

You say that during the spin transfer stage, the spinning disks will change velocity with a force. Then you say imagine some other scenario where the attributed force has directional vector. Then you argue that since that in your scenario there is a force with a directional vector then it must be applied to parts that are spun up with a motor. Since I think that spinning disks with a motor wont accelerate them in a direction, you say that the motor doesn't matter. Since the only force on the disks during the spin transfer stage is from the motor, I think it would matter. Then you say that the force just happens, (from nowhere?) Then you have the gall to say that I don't understand basic physics. I think that you believe it won't work and since you can't explain it you resort to defamation. well, if it works for you then good luck with that.
23. ## Does a spinning disk gain relativistic mass

I'm not that rich, but you implying that they are untestable was just stupid. I assume you meant the phrase from Wolfgang Pauli in regards to something that is untestable or will not fail any test. clarify what you meant.
24. ## Does a spinning disk gain relativistic mass

It seems you think these thing are untestable? why could you not do an experiment to see if a spinning disk would change velocity just by spinning it? why could you not do an experiment to see if transferring energy using AC causes acceleration in the wire? why could you not do an experiment to see if you could accelerate a system using realtivistic mass due to spinning disks?
25. ## Does a spinning disk gain relativistic mass

the similarities are the mass transfer, but since the energy is transferred by torque, the directional velocities do not speed up or slow down the disks. But with the skaters and bowling ball, the bowling ball slows and speeds up the skaters because the bowling ball has a direction and speed to add or subtract from the velocities of the skaters.
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