- #1

- 214

- 10

What force I can use in calculating Young's Modulus and why?

my doubt is whether it will be 3N or 1.5N and why?

Stretched length is given.

- Thread starter gianeshwar
- Start date

- #1

- 214

- 10

What force I can use in calculating Young's Modulus and why?

my doubt is whether it will be 3N or 1.5N and why?

Stretched length is given.

- #2

berkeman

Mentor

- 58,180

- 8,241

It will be accelerated by a = F/m, not sitting still on the table, no?

What force I can use in calculating Young's Modulus and why?

my doubt is whether it will be 3N or 1.5N and why?

Stretched length is given.

- #3

- 214

- 10

Thanks! I want to know value of force i.e., 1.5f or 3f.It will be accelerated by a = F/m, not sitting still on the table, no?

- #4

- 309

- 38

https://en.wikipedia.org/w/index.php?title=Newton's_laws_of_motion&redirect=no#Newton.27s_3rd_Law

- #5

- 214

- 10

Then how can I calculate Young's modulus only under these given conditions.

- #6

- 309

- 38

- #7

- 214

- 10

I need to find tensile stress on rod as I want to find elongation for calculating young's modulus

- #8

billy_joule

Science Advisor

- 1,200

- 330

The tensile stress will vary throughout the length of the rod...density & some calculus is needed.I need to find tensile stress on rod as I want to find elongation for calculating young's modulus

Have you done any elongation or stress of a rotating rod type questions? This are similar.

- #9

- 214

- 10

- #10

- 214

- 10

Thanks billy! I have not done many problems as you asked.

- #11

- 214

- 10

Stating same problem in a different wayhttps://mmi240.whatsapp.net/d/yywezFW6TcxsIWacjmME81VjKfY/AunnYXfkq2P8Blmy__wJQyRLQ4aL4z8kQXlZUs2wGVPB.jpg [Broken]

Last edited by a moderator:

- #12

- 214

- 10

https://mmi130.whatsapp.net/d/l-CffzhTrS1R5PpPeDk30FVjLnU/Ard1QFFL7XB255nzwRl_0yw8Xxy2I-ChbVHnl1qLgWAY.jpg [Broken]

Last edited by a moderator:

- #13

- 16,829

- 6,650

No, as was stated earlier, you need to take into account that the tension varies throughout the rod.

- #14

- 214

- 10

Then here in new case answer is F?

- #15

billy_joule

Science Advisor

- 1,200

- 330

No.Then here in new case answer is F?

Imagine accelerating a long chain by pulling one end. Where is the chain most likely to break?The tensile stress will vary throughout the length of the rod...density & some calculus is needed.

Have you done any elongation or stress of a rotating rod type questions? This are similar.

The first link must support every other link. The last link supports only it's own self weight. Therefore, the stress & elongation in each link is not the same.

Your problem looks at a chain with an opposing force on the last link.

You need to analyse an infinitesimal section of your bar, set up an integral, find the integration constant from the boundary conditions, perform the integration over the length of the bar. (Or similar, It's been a while for me..)

Every decent mechanics of materials textbook (I found Hibbeler good) will likely have multiple examples of the very similar rotating bar situation.

- #16

- 214

- 10

Also I want to know whether my question has a simple answer or the question is not complete or the question is irrelevant......(restated question)

- #17

billy_joule

Science Advisor

- 1,200

- 330

They are very similar because they are analysed in a similar way.Thanks!Why are you saying "very similar rotating bar". Specifically rotating.

http://www.mathalino.com/reviewer/m...als/solution-to-problem-218-axial-deformation

and exe 1.296 here

http://exir.ru/solutions/Elastic_Deformations_of_Solid_Body.htm

There is enough information given to reach a meaningful answer. Whether it's simple or not would depend on the student.Also I want to know whether my question has a simple answer or the question is not complete or the question is irrelevant......(restated question)

- #18

- 214

- 10

Thank you billy!

- Last Post

- Replies
- 3

- Views
- 10K

- Last Post

- Replies
- 2

- Views
- 2K

- Last Post

- Replies
- 1

- Views
- 3K

- Last Post

- Replies
- 3

- Views
- 4K

- Last Post

- Replies
- 2

- Views
- 731

- Last Post

- Replies
- 7

- Views
- 24K

- Replies
- 8

- Views
- 1K

- Last Post

- Replies
- 7

- Views
- 26K

- Replies
- 1

- Views
- 1K

- Last Post

- Replies
- 2

- Views
- 5K