Timeline for Is there a principle that determines the tension in this system?
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
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| Dec 7 at 1:50 | comment | added | KDP | @BobD I have added a second answer that specifically examines the hypothetical rigid case in detail, that might be of interest. | |
| Dec 6 at 15:51 | comment | added | KDP | @BobD Jeet had already deducted the answer to the book question. Rather than just repeat what he had already worked out for himself, I thought it would be instructive to explore alternative interpretations and other possible solutions. There was a similar discussion in this related question: physics.stackexchange.com/a/594773/388464 Sammy Gerbil commented: "The purpose of this site is to discuss what is correct physics, not to advise students how to pass tests." I tend to agree. | |
| Dec 6 at 13:18 | comment | added | Vincent Thacker | @BobD The point is that if the strings are completely inextensible, when pulled, the system is essentially one rigid body. The three blocks either all move or all remain stationary. This can only be described by the total friction. There is no more information to be obtained. There are infinitely many ways to distribute it among any constituent components. | |
| Dec 6 at 11:59 | comment | added | Bob D | Problems like this are rarely intended to be realistic. The acceptable answers to the problem tells me the strings are assumed initially their natural length and that they are also considered inextensible, so that there is no actual movement of the blocks, just the transmission of tension when the friction is limiting value. To have to assume a kinetic coefficient to solve the problem as you did seems like a stretch, IMO (pun intended!). | |
| Dec 6 at 11:12 | comment | added | KDP | @BobD Yes, I am assuming that. Even if the strings were extended, if they are realistic strings, they will stretch a certain amount so the blocks will still move a certain amount relative to each other. | |
| Dec 6 at 10:42 | comment | added | Bob D | Your answer seems to assume the strings between the blocks are not initially extended to their natural length so that the first two blocks are initially free to move if the limiting static friction force is exceeded. Is that correct? | |
| Dec 6 at 5:40 | comment | added | Jeet | Thank you for the answer! The other question you answered was helpful too. | |
| Dec 6 at 5:37 | vote | accept | Jeet | ||
| Dec 6 at 5:16 | vote | accept | Jeet | ||
| Dec 6 at 5:16 | |||||
| Dec 5 at 22:20 | history | edited | KDP | CC BY-SA 4.0 |
added 524 characters in body
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| Dec 5 at 22:11 | history | answered | KDP | CC BY-SA 4.0 |