- #36
Delta2
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As I had suspected, something tells me that @aang hasn't been taught about virtual work . But I might be wrong.haruspex said:Virtual work.
As I had suspected, something tells me that @aang hasn't been taught about virtual work . But I might be wrong.haruspex said:Virtual work.
For this question at least, it doesn’t seem to me it is something that needs to have been taught. Isn't it evident that if even the slightest displacement of the plate (in some direction) lowers its mass centre then it is not at equilibrium?Delta2 said:As I had suspected, something tells me that @aang hasn't been taught about virtual work . But I might be wrong.
No that doesn't seem so obvious to me but that's my subjective view, most people might find it obvious, I can't tell.haruspex said:For this question at least, it doesn’t seem to me it is something that needs to have been taught. Isn't it evident that if even the slightest displacement of the plate (in some direction) lowers its mass centre then it is not at equilibrium?
Think of it this way... suppose the least displacement to the right lowers the mass centre and so, the derivative being smooth, the least displacement to the left raises the mass centre. So displacing to the left does work, and it can only do that by opposing a force. So there must be a net force on the object to the right.Delta2 said:No that doesn't seem so obvious to me but that's my subjective view, most people might find it obvious, I can't tell.
No, that is incorrect, and there is still a way to go.aang said:H wrt THETA=L/2*COSθ
IS IT CORRECT.
ARE WE NEAR THE SOLUTION
Right. And since we want the extremum of H that derivative is zero.aang said:H wrt THETA=L/2*COSθ+SINβ* x'
You have a sign error in the second equation.aang said:LCOSθ=x'*SINα-y'*SINβ
-LSINθ=x'*COSα-y'*COSβ
HOW MUCH FURTHER.