How Much Does a Steel Wire Stretch When Supporting Moving Masses?

Click For Summary
The discussion focuses on calculating the stretch of a steel wire supporting two moving masses over a pulley. A 1.80-m long wire with a diameter of 0.80 mm is used, with one end attached to a 23.0-kg mass and the other to a 14.0-kg mass. The tension in the wire is calculated to be 171 N, leading to a tensile stress of approximately 340,163 N/m². Participants clarify that this stress should be used in conjunction with Young's modulus for steel (210 GN/m²) to determine the wire's stretch. The conversation emphasizes the importance of correctly applying the formulas for stress and strain to find the final stretch value.
kopinator
Messages
41
Reaction score
1
A 1.80-m long round steel wire with a cross-sectional diameter of 0.80 mm is placed over a light frictionless pulley, with one end of the wire connected to a 23.0-kg mass and the other end connected to a 14.0-kg mass. By how much does the wire stretch when the masses are in motion? S= F/A
e= ΔL/L°
S= Ye (where Y is Young's modulus for steel= 210 GN/m^2)

I figured the F i needed in the first equation would be the tension in the wire. I got 171N for that answer and then I applied it to S= F/A. I found my S to be about 340163 N/m^2. I don't know whether to use that S for S=Ye or not. Where do I go from here?
 
Last edited:
Physics news on Phys.org
I haven't check your numbers, but yes, the tensile stress is the tension force divided by the cross-sectional area, and this is the stress that goes into your equation involving young's modulus.
 

Similar threads

  • · Replies 19 ·
Replies
19
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
7K
  • · Replies 4 ·
Replies
4
Views
8K
Replies
1
Views
5K
  • · Replies 5 ·
Replies
5
Views
4K
Replies
3
Views
2K
  • · Replies 9 ·
Replies
9
Views
5K
  • · Replies 14 ·
Replies
14
Views
5K
Replies
1
Views
3K