[PHYSICS] How to calculate the extension of a wire.

Watch
Borg_Jake
Badges: 0
Rep:
?
#1
Report Thread starter 3 years ago
#1
Hey, I have my physics exam within the week, and my teacher did not really explain the topic of "Extension" that well. I have been doing some physics past papers, and have stumbled upon this question.

A load of 60N is applied yo a steel wire of length 2m and cross-section area of 0.22mm^2. the Young's modulus of steel is 210GPa. What is the extension produced?

Could someone please show me how to carry out this problem?
Thanks a lot
0
reply
GotMyIonYou
Badges: 4
Rep:
?
#2
Report 3 years ago
#2
Strain is the extension per unit original (unstretched) length. Strain = x/L
Stress is the force per unit cross-sectional area. Stress = F/A
Young's Modulus = Stress/Strain

Quite a common question from when I've been doing some papers. Basically you are working backwards from the Young's Modulus. You can do it two ways.
Substitute both equations for stress and strain into the Young's Modulus equation and rearrange for x if you are happy with algebra
Or doing it in stages you can calculate:
- Stress
- Strain
- Then extension

Be careful with your units , would also be a good idea to make sure you understand the various stress/strain graphs and how they relate to the materials properties (brittle/ductile, ultimate tensile strength, plastic/elastic), also comes up quite often
2
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Current uni students - are you thinking of dropping out of university?

Yes, I'm seriously considering dropping out (147)
14.54%
I'm not sure (43)
4.25%
No, I'm going to stick it out for now (303)
29.97%
I have already dropped out (26)
2.57%
I'm not a current university student (492)
48.66%

Watched Threads

View All