- #1
Adesh
- 735
- 191
I'm posting the images of "Sommerfeld's Lectures on Theoretical Physics, Vol 2, Mechanics of Deformable Bodies"
I apologize for posting the images rather than writing out the whole thing. But I did it to so that nothing should be missed, as writing out the whole thing is subjected to errors.
I'm having problems in the argument which he has made (the blue box in second picture). How can we use Newton's 3rd Law when it is a consequence of deformation of bodies? A.P. French supports this statement by saying
When I have a spring attached at one end, and if I pull the other end we know that a restoring force will come into play and in equilibrium this restoring force will be equal to the applied force and hence we got Newton's 3rd Law , Action = Reaction ! But in the analysis above we have taken it to be true, why? I'm finding it hard to accept how "positive x-surface" will apply the same force on "negative x-surface" by the means of Newton's 3rd Law. Is there any other argument which can be used to say "force of negative x-surface will be same as it was on positive x-surface" ?
Thank you.
I apologize for posting the images rather than writing out the whole thing. But I did it to so that nothing should be missed, as writing out the whole thing is subjected to errors.
I'm having problems in the argument which he has made (the blue box in second picture). How can we use Newton's 3rd Law when it is a consequence of deformation of bodies? A.P. French supports this statement by saying
The production of a force of reaction in response to an applied force always involves deformation to some extent.
When I have a spring attached at one end, and if I pull the other end we know that a restoring force will come into play and in equilibrium this restoring force will be equal to the applied force and hence we got Newton's 3rd Law , Action = Reaction ! But in the analysis above we have taken it to be true, why? I'm finding it hard to accept how "positive x-surface" will apply the same force on "negative x-surface" by the means of Newton's 3rd Law. Is there any other argument which can be used to say "force of negative x-surface will be same as it was on positive x-surface" ?
Thank you.