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# AS stress and strain question

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1. the question is :
a steel wire of diameter 1mm is fastened horizontally to 2 rigid supports separated by 2m. the initial tension is negligible as is the sag in the wire.
A load mass 0.10kg is suspended from the midpoint of the wire, which caused the wire to deflect downwards by 2.0 cm at that point.
calculate
a) the tension in the wire
b) the young's modulus of the material of the wire

i've drawn and attached the diagram.

thanks for all the help!
Attached Images

2. (Original post by Exotic-L)
the question is :
a steel wire of diameter 1mm is fastened horizontally to 2 rigid supports separated by 2m. the initial tension is negligible as is the sag in the wire.
A load mass 0.10kg is suspended from the midpoint of the wire, which caused the wire to deflect downwards by 2.0 cm at that point.
calculate
a) the tension in the wire
b) the young's modulus of the material of the wire

i've drawn and attached the diagram.

thanks for all the help!
What have you tried to do? For the first part, you need to balance forces. For the second the first thing to do is calculate the extension (and hence the strain) of the wire. If you need help doing this, just ask.
3. (Original post by lerjj)
What have you tried to do? For the first part, you need to balance forces. For the second the first thing to do is calculate the extension (and hence the strain) of the wire. If you need help doing this, just ask.
i dont know what i should do to balance the forces, but i was trying to find the vertical component of the cables because the vertical component of each cable is equal to half the weight of the object. but as the angles were not given i didnt know how to continue
can you work me through the question please
4. (Original post by Exotic-L)
i dont know what i should do to balance the forces, but i was trying to find the vertical component of the cables because the vertical component of each cable is equal to half the weight of the object. but as the angles were not given i didnt know how to continue
can you work me through the question please
Ok, so the initial length of the wire was 2m, and you've stretched it down by 2cm in the middle. If you draw in a vertical line to split your diagram up into two triangles they should have a base of 100cm and height 2cm.

From this you can calculate the length of the hypotenuse using Pythagoras OR you can choose to find the angle using tan^-1(), whichever you prefer. Then you can find total tension.
5. (Original post by lerjj)
Ok, so the initial length of the wire was 2m, and you've stretched it down by 2cm in the middle. If you draw in a vertical line to split your diagram up into two triangles they should have a base of 100cm and height 2cm.

From this you can calculate the length of the hypotenuse using Pythagoras OR you can choose to find the angle using tan^-1(), whichever you prefer. Then you can find total tension.
thank you!!
but im not getting the correct ans
6. (Original post by Exotic-L)
thank you!!
but im not getting the correct ans
what would the correct answer be?
7. (Original post by Insia786)
(Original post by thefatone)
what would the correct answer be?
a) 24.5N
b)156Gpa
8. Can you show me ur. Workings for this pls

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