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Quote from: Jaaanosik on 01/05/2020 04:13:30Is the wheel going to jump up due to the angular acceleration/deceleration, assuming angular acceleration is bigger than gravitational acceleration?You know it will not.The fact that you got the α and ω vectors correct suggests you're not completely uneducated, and yet you ask a question like that. Now why is that?For the third time, you are adding vectors of different units (bold above), meaning you're ignoring everything I say and intend to continue to do so. Hence I see no reason to continue this troll discussion.
Is the wheel going to jump up due to the angular acceleration/deceleration, assuming angular acceleration is bigger than gravitational acceleration?
Please, tell me a good reason why the wheel is not going to jump up if the angular acceleration a is bigger than gravitational g?
I assure you, this is not trolling.
Quote from: Jaaanosik on 01/05/2020 15:18:15Please, tell me a good reason why the wheel is not going to jump up if the angular acceleration a is bigger than gravitational g?Quote from: Jaaanosik on 01/05/2020 15:18:15I assure you, this is not trolling.It is trolling, because regardless of ANY information you're given you will continue to maintain that the conservation of momentum does not hold.
Bobolink,on the contrary, if you say that the wheel is not going to jump up then you are defending position that the conservation of the momentum does not hold,
Quote from: Jaaanosik on 01/05/2020 17:30:26Bobolink,on the contrary, if you say that the wheel is not going to jump up then you are defending position that the conservation of the momentum does not hold,LOL!
It amazes me that even after so much explanation, you still just don't understand angular momentum.
Really?Please, explain how the cube can fly above the table?What caused the jump?How is it going to be different from my explanation?Jano
2:50min into the video, how is it possible that the cube jumps?
Quote from: Jaaanosik on 01/05/2020 19:54:572:50min into the video, how is it possible that the cube jumps?Hint: It wouldn't jump anywhere in a freefall reference frame.
Quote from: Halc on 01/05/2020 12:30:02Quote from: Jaaanosik on 01/05/2020 04:13:30Is the wheel going to jump up due to the angular acceleration/deceleration, assuming angular acceleration is bigger than gravitational acceleration?You know it will not.The fact that you got the α and ω vectors correct suggests you're not completely uneducated, and yet you ask a question like that. Now why is that?For the third time, you are adding vectors of different units (bold above), meaning you're ignoring everything I say and intend to continue to do so. Hence I see no reason to continue this troll discussion.Halc,I assure you, this is not trolling.Please, have a look:https://en.wikipedia.org/wiki/TorqueThe figure shows the setup from my question.If we take a realistic time, let's say dt = 0.1s for the braking.When Torque - T, Omega - w, Inertia - I, Angular acceleration - aT = I (dw/dt) + (dI/dt) wWe know that dI/dt = 0 during the breaking, so the torqueT = I (dw/dt)or T = I aPlease, tell me a good reason why the wheel is not going to jump up if the angular acceleration a is bigger than gravitational g?Jano
It seems to me you've misunderstood L (angular momentum).The right hand rule as applied to rotation is essentially a mathematical artifact of a cross product.That the pseudovector L appears to have a "direction" does not imply a force in that direction, in the way you're thinking.Why would L be a force up or down, due to the disk spinning?The pseudovector L (being a vector) is more about resistance to a change in the orientation of that vector. e.g. like a gyro wanting to keep spinning in its plane.When the brakes are applied to your spinning disk, it won't move up (or down).(Edit: removed section too easily misconstrued.)
A bicycle and a spinning office chair would be enough to put aside this silly idea of a braked wheel experiencing a force in the direction of L.
Quote from: pzkpfw on 04/05/2020 00:40:48A bicycle and a spinning office chair would be enough to put aside this silly idea of a braked wheel experiencing a force in the direction of L.He hasn't explicitly mentioned that since post 252.Still trolling however. Most recent post had at least four errors, one of which was the lack of direct relevance of the videos to the situation being discussed.I find it best to just not feed the trolls. He's not here to learn anything, only to push our collective buttons and get his jollies from those who continue to respond.I try to respond to intelligent questions, but the last several post have neither asked questions nor displayed any deliberate intelligence.
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.
https: //www.youtube.com/watch?v=qS_dcNqs3d4Physics - Mechanics: The Gyroscope (3 of 5) The Torque of a Spinning Gyroscope
The top view of the wheel. The darker gray balls represent two centers of mass of two halves of the wheel.The orange vectors are torques positioned at the same position as in the second video.