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Quote from: Jaaanosik on 04/05/2020 14:58:35Please, point the errors or otherwise your posts are trolling,Error 6: Failure to respond to a troll is not in itself trolling. It is doing the troll and the rest of the world a service, similar to abstinence of feeding wild geese.If you wish a response, show some intelligence in your posts, not goose droppings.Quote from: Jaaanosik on 03/05/2020 05:17:54The torque is a real force1: Continued equivocation of force and torque, despite numerous posts informing you of this error.Quoteduring the braking of the wheel otherwise we would not have the gyro precession.2: Braking of the wheel does not cause gyro precession....
Please, point the errors or otherwise your posts are trolling,
The torque is a real force
during the braking of the wheel otherwise we would not have the gyro precession.
I'd like to answer 1 and 2 first.Quote from: HalcContinued equivocation of force and torqueIf torque is not a real force then what is preventing the guy to rotate the wheel against the torque (precession direction) at 2:50 min in this video?
Continued equivocation of force and torque
Quote from: Halc2: Braking of the wheel does not cause gyro precession.The arm (r) of the assembly is like a spoke of a bigger 'wheel'.The rotation of this 'virtual wheel' is in the F=mg direction, down.
2: Braking of the wheel does not cause gyro precession.
The gyro wheel angular momentum L is 'breaking', preventing the free fall, this generates the torque.
...QuoteThe gyro wheel angular momentum L is 'breaking', preventing the free fall, this generates the torque.Braking requires motion and friction resisting (slowing) that motion. There is no downward motion to resist in this situation, and the assembly is assumed to be free of friction. Yes, toy gyros slow over time and eventually fall. The ones in space stations run in a vacuum and do so for years. There's nothing being slowed down, hence the video does not depict your 'braking' scenario where energy is being dissipated by friction. It is an irrelevant choice of videos to make the (incorrect) point you were attempting....
Quote from: Jaaanosik on 04/05/2020 21:05:30The torque is a rotational inertia multiplied by an angular acceleration.There is a torque therefore there has to be an angular acceleration.Please, show us, where is the angular acceleration so we can have the torque?Read my 4th paragraph in the previous reply, which answers exactly this. It shows the resulting angular acceleration.
The torque is a rotational inertia multiplied by an angular acceleration.There is a torque therefore there has to be an angular acceleration.Please, show us, where is the angular acceleration so we can have the torque?
Professor Lewin says: "There is no net force on that wheel, but there is a net torque."What is a net torque? Out of nothing?
We can see, that if the torque is not there then there is no precession, minute 48.The wheel is stable, no net force without the additional weight on the axle.Also the wheel is stable no net force with the additional weight on the axle with the precession.
What are the causes of the precession effect?
The external torque on the angular momentum of a rotating wheel.
Both are required, if one is missing then there is no precession.
I didn't respond to several posts due to obvious lack of reading prior responses.You're still assuming that force is torque, which is going to give you wrong answers every time.Quote from: Jaaanosik on 08/05/2020 15:59:57Professor Lewin says: "There is no net force on that wheel, but there is a net torque."What is a net torque? Out of nothing?Net torque means that the sum of the torque vectors acting on the wheel is nonzero. No, those torques must be transferred to the wheel. Conservation of angular momentum does not allow torque 'out of nothing'.He also says net force is zero, meaning the sum of the force vectors is zero. The force vectors are obviously not the torque vectors, since (the part you never remember) force is not torque....
Quote from: Jaaanosik on 09/05/2020 16:42:21The kinetic energy comes from a force in mechanical systems.Forces are involved to change kinetic energy, but net forces are not necessarily involved. Torque is not force, and yet X torque applied for time T to a system can (doesn't necessarily) result in some amount of kinetic energy change to the system regardless of the magnitude of the forces used to achive said X torque.Anyway, in context of your post here, I know what you mean.QuoteWhen professor releases the weight from his hand the weight and the axle start to rotate, they have the rotational kinetic energy.Where did the rotational kinetic energy come from?The precessing disk applied a momentary torque (not any net force) to the axle. No continued torque is required once the axle gets its steady state angular momentum (a small vector pointing down)
The kinetic energy comes from a force in mechanical systems.
When professor releases the weight from his hand the weight and the axle start to rotate, they have the rotational kinetic energy.Where did the rotational kinetic energy come from?
There is only rotating disk/wheel in the beginning. Professor even says that the rotating wheel is suspended in such a way that there is no gravitational torque on it, 47:14 min.
The rotating disk cannot provide/cause a torque.
It is steady by itself, just a constant angular velocity.It does not have units of measure for it, does it?
You are right, small vector pointing down. There had to be I*a (rotational inertia * angular acceleration); what is the cause?The only cause is a net force.
An object cannot start rotating without a net force.
The w_precession = T/L torque over the rotational inertia of the wheel.
Therefore: "The precessing disk applied a momentary torque (not any net force) to the axle. No continued torque is required once the axle gets its steady state angular momentum (a small vector pointing down)"is wrong. It is not a momentary torque. It is a constant torque.
You can attach the weight to the rotating wheel axle on the ISS and it is not going to precess
...]The angular velocity of the axle is constant, changing only when the weight is added or removed. That means the torque is momentary. No additional torque is needed to rotate something that's already rotating. Instead of asserting all these things, why don't you consider the implications of your assertions, which run into contradictions. If there is continuous torque on the axle, why does its angular velocity not change after that moment when the weight is added. That's would be a contradiction.QuoteYou can attach the weight to the rotating wheel axle on the ISS and it is not going to precessThere is no weight on the ISS....