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Quote from: Yahya on 29/07/2018 19:33:15Quote from: Bored chemist on 29/07/2018 19:30:24And it's the fact that you are pretending that you know about this stuff.I know free fall I know net force I know all classical mechanics Then why do you keep getting it wrong?Maybe it's thisQuote from: Bored chemist on 29/07/2018 19:30:24And it's the fact that you are pretending that you know about this stuff.
Quote from: Bored chemist on 29/07/2018 19:30:24And it's the fact that you are pretending that you know about this stuff.I know free fall I know net force I know all classical mechanics
And it's the fact that you are pretending that you know about this stuff.
I get it right and the net force is bigger than F=ma
Quote from: Yahya on 29/07/2018 20:17:02I get it right and the net force is bigger than F=maSo you think you are right and Newton got it wrong.Do you think that's likely?
Quote from: Bored chemist on 29/07/2018 20:27:35Quote from: Yahya on 29/07/2018 20:17:02I get it right and the net force is bigger than F=maSo you think you are right and Newton got it wrong.Do you think that's likely?He might missed it.
you are pretending that you know about this stuff.
Quote from: Yahya on 29/07/2018 20:43:48Quote from: Bored chemist on 29/07/2018 20:27:35Quote from: Yahya on 29/07/2018 20:17:02I get it right and the net force is bigger than F=maSo you think you are right and Newton got it wrong.Do you think that's likely?He might missed it.you are the first to notice the mistake in 400 years or so?Do you think that's likely?
I'm actually the first one to notice it
Quote from: Yahya on 29/07/2018 21:04:18I'm actually the first one to notice itDo you know that, when Newton published his stuff, he wasn't popular? Lots of the scientists of the day tried to prove him wrong.And you- in spite of the fact that you have been told why you are wrong (and Newton is right)- still think that you are the only person in roughly 400 years, to spot that he made a mistake in one of the best known, and most widely used equations in physics.OK,What are you drinking/ smoking/ snorting/ whatever?
I do not understand your first two paragraphs.
So what is net force on mass 2 kg ? it is obvious that it is 6 Newtons because I could lift a weight of 6 N with the output gear, however the gearbox is for speed reduction so the acceleration is 1/6 m/s.s now F=ma:
Mass on gearbox for speed reduction undergoes large "net force because I could lift weight with this force " but it seems there is something stopping it from accelerating in a way F=ma is not valid.
Quote from: Yahya on 30/07/2018 07:17:50So what is net force on mass 2 kg ? it is obvious that it is 6 Newtons because I could lift a weight of 6 N with the output gear, however the gearbox is for speed reduction so the acceleration is 1/6 m/s.s now F=ma:This is where you are going wrong. Although the gear could apply 6N it isn’t because the acceleration of the mass is constrained by the speed limitation.If you connect the gear to the 2kg via a horizontal string (to remove red herring of freefall and gravity) and a spring balance then the gear will accelerate the mass at 1/6m/s2 and (ignoring friction) the force recorded by the balance will show F=ma ie 0.333=2/6
Quote from: Colin2B on 30/07/2018 10:44:00Quote from: Yahya on 30/07/2018 07:17:50So what is net force on mass 2 kg ? it is obvious that it is 6 Newtons because I could lift a weight of 6 N with the output gear, however the gearbox is for speed reduction so the acceleration is 1/6 m/s.s now F=ma:This is where you are going wrong. Although the gear could apply 6N it isn’t because the acceleration of the mass is constrained by the speed limitation.If you connect the gear to the 2kg via a horizontal string (to remove red herring of freefall and gravity) and a spring balance then the gear will accelerate the mass at 1/6m/s2 and (ignoring friction) the force recorded by the balance will show F=ma ie 0.333=2/6 The force recorded by the balance won't read 2/6 N it would read 6 N.
The force recorded by the balance won't read 2/6 N it would read 6 N.
As @The Spoon says “show your workings”.
Quote from: Colin2B on 30/07/2018 14:37:58As @The Spoon says “show your workings”.I have two electronic scales , what I going to do is exerting force on input gearbox with one and read output gearbox force with the other.
Quote from: Yahya on 30/07/2018 14:56:32Quote from: Colin2B on 30/07/2018 14:37:58As @The Spoon says “show your workings”.I have two electronic scales , what I going to do is exerting force on input gearbox with one and read output gearbox force with the other.No good if you fix the end of the output scale as you are only measuring static forces rather than dynamic acceleration force. I would have thought that was obvious.
Net force = (ratio-1)F1+F2F2= mass times acceleration of the output gear.F1=force on the input gear if the ratio is 1:1 then the net force only equals F2= maif output mass is 0 also there would be force .
I have a gear box of speed reduction of ratio 1:6 , I have input force of 1 N the output force would be 6 newton
Quote from: Yahya on 30/07/2018 07:17:50I have a gear box of speed reduction of ratio 1:6 , I have input force of 1 N the output force would be 6 newtonThen the gearbox will rotate, get squashed or move .It depends on the directions + points of application of teh forces.If you had a gearbox floating in space and pushed it, what would happen?Well that's the problem- you need to consider the the forces on it and, to a good approximation they will also add to somewhere tween 5 and 7 N.The gearbox is fixed to the ground.The forces supplied by the bolts holding t in place are very nearly the same as the forces applied to teh box.So, the net force on the gearbox is zero.That's sensible.It's why the box doesn't actually accelerate.
Quote from: Yahya on 29/07/2018 20:43:48Quote from: Bored chemist on 29/07/2018 20:27:35Quote from: Yahya on 29/07/2018 20:17:02I get it right and the net force is bigger than F=maSo you think you are right and Newton got it wrong.Do you think that's likely?He might missed it.And, in spite of the fact that practically every engineer and physicist since then has used gears many times, and studied them + done exam questions about them, you are the first to notice the mistake in 400 years or so?Do you think that's likely?