The book is called, "The Machine Design Problem Solver" page 215, and there is no consideration of friction mentioned at all. Of course both the bolt and the members are considered as elastic (hence the reference to their stiffnesses). I have not left out anything that I can see. The entire...
Hello,
I am studying through a machine design book and ran across this confusing statement which summarizes the results of an example problem. The problem has a bolt and nut that together hold two members in compression. The stiffness ratio is given as $$K_m = 6K_b$$. The bolt is preloaded with...
The system is shown below. It consists of a rod of length ##L## and mass ##m_b## connecting a disk of radius ##R## and mass ##m_d## to a collar of mass ##m_c## which is in turn free to slide without friction on a vertical and rigid pole. The disk rolls without slipping on the floor. The ends...
Interesting tidbit. Of course, if you had bothered to read any of the above, you'd know that I am clearly not asking, "show me how this works quantitatively without math." You really think a physically intuitive explanation is the very same thing as a quantitative explanation? Wow. They are not...
And I apologize. I didn't realize we were on an elementary school playground, where we pretend that because someone has a particular thing in mind and is not interested in your approach, that he thus "has such a fear" of anything. What a jerk! Please refrain from ever "helping" me again.
I was...
Platitudes? You must be having a rough day! If you haven't learned that physics is not merely math, then I definitely can't help you. Yet it is. I'm sorry you think the search for insight beyond number crunching is trite.
Nobody else was required to provide calculations when claiming that any...
I am not sure what you mean by, "Eh?" above. See the previous replies where I was told this technique lets you use "any coordinates you like" and similar. Your comment that L*d(phi)/dt will not work for any other angle (other than phi+C) contradicts what others have said. Mysticism is not any...
Thanks everyone.
The consensus seems to be that picking any random angle "just works" for any problem, whether there is any physically interpretable reason apparent or not. So, one could use the angle the top surface makes with the ground, either of the other two angles in the triangle I drew...
Thank you for replying! I do agree with you about generalized coordinates and their usefulness. However, I think you missed the point.
My question is specifically about how it can be correct to describe the translational velocity of the center of mass by using an angle that is not the angle...
I am looking at a textbook solution to the following problem of finding the equation of motion of a half disk. In the solution, the author considers the half disk has a COM at the black dot, and to find the instantaneous translational velocity of the center of mass (he considers rotational...
Thanks. That is one of the pages I looked at when trying to understand. The problem is that both beams I show are consistent with the "two useful hints" or "guidelines" the author lists. There is no explanation regarding either of my questions.
In an I-beam, the shear flow is usually shown drawn as on the left, not as drawn on the right. I do not understand why. I do understand:
The total horizontal shear force must be zero, consistent with statics.This is satisfied in both images.
The vertical direction matches the direction of the...
Thanks, Master1022.
As for the part at the end, I was just doing a force balance on the cut section. I may have made a mistake there, but I don't see it yet. I appreciate your checking this out!
A force balance on the entire structure shows that these compoments are correct. The Cy is only the reaction of pin C on member CDE. There is another member that has a Cy too (member CBA).