Roll on the 20th June

[tbnz]

It's hard not to when quite obviously purepower is a total try hard.

purepower, go hang out with your mates IdiotDJByNight and Newtonian Loser.

[purepower]

@Libra & sm0ky2

Actually, on a perfectly balanced wheel, with two perfectly equal weights placed directly across from each other at the exact same distance from the center, the wheel would not rotate at all, regardless of the position they start in. Ill quote myself from a previous post that apples here:

"Moment=(force)*(distance)*[cos(angle)]

For a balanced system:

Moment1=Moment2 ==>

(force1)*(distance1)*[cos(angle)]=(force2)*(distance2)*[cos(angle)] ==>
(g*mass1)*(distance1)*[cos(angle)]=(g*mass2)*(distance2)*[cos(angle)]
(cos(angle) and g drop out as they appear on both sides) ==>

(mass1)*(distance1)=(mass2)*(distance2)"

In the picture, you can see that if the lengths are equal and the masses are equal, the torques would be equal and opposite and produce no motion. For those of you seeing motion, check your distances and masses. Even a half centimeter or gram difference could be enough to produce motion.

Sm0ky, you were correct in your understanding of the moment of inertia. This, plus friction, could potentially stop an unbalanced wheel from rotating.

Your energy analysis is correct too, but with one exception. Your datum doesnt have to be measured from the center and could be measured from the ground, table, or whatever. This is because we will always be measuring the change in height for our change in energy, so as long as our datum remains the same we can take it from where ever we want.

I have shown you the free body diagram (force analysis) proves there will be no rotation for a balanced system. Now to show you the energy analysis proves there will be no rotation for a balanced system.

E=m*g*h

So total energy for the system in the second picture, part 1, is (assume masses are equal):

E(tot-1) = (mass)*(g)*(height1)+(mass)*(g)*(height2) ==>

E(tot-1)= (height1+height2)*(mass)*g


Now for the second part (assume masses are equal):

E(tot-2) = (mass)*(g)*(height1+deltaH)+(mass)*(g)*(height2-deltaH) ==>
E(tot-1)= [(height1+deltaH)+(height2-deltaH)]*(mass)*g ==>
E(tot-1)= [height1+height2+deltaH-deltaH]*(mass)*g ==>

E(tot-2)= (height1+height2)*(mass)*g

As you can see, the total energy in systems 1 and 2 are equal! But since energy would have to be used to overcome friction and inertia, the wheel will be happy to stay right where it is at. No rotation, shown two ways.

[purepower]

Hi All
My math was just pointing out the 20 to 1 is not real when you take the beam into acount all the 20ks is doing is evening everything out so anything put on the other end will unbalance the lever and it will move lifting the small end  the 20 to 1 is an illusion.
Take Care all
Graham

Im glad you see the light! And this, coming from a non-"oil guy"..

[Rusty_Springs]

Hi All
Again your right Power, I can add a weight at 1 and the wheel will move to 6 I can add a weight at 7 and it will move to 6 but if I add them together at 1 and 7 and there the same weight and the wheel is perfectly balanced you get no movement what so ever, like Power said if your getting movement your wheel isn't perfectly balanced.
Take Care All
Graham

[purepower]

golly - u r sure a smarty-pants
yes - weve been waiting for you glory to show us the proof - waiting and wanting from the start - gagg cough
who dies and makes u god and say what we talk about
u r so expert thank you thank you for the offer
yes - does your shit stink?  i smells it from here!

Seriously, what's your problem? Is it that you cant fathom someone genuinely helping to educate others? Is it that I am right in what I say and you have never know what thats like? This isn't middle school, stop picking on the smart kids...

Evg said:
"Do we have to pick on Purepower, like others pick on Archer?
Just a thank you for your info to both parties would be nice"

Thank you. I seriously dont understand the hostility directed towards me. I have never cursed and never made any personal attacks (I have attacked statements, but nothing personal), yet I seem to be catching the most. I just dont understand what people have against me...

And I never said they had to stop talking about it. I do recall a "please" in that sentence.