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# Force and Elastic Calculation! Watch

1. A wire of length 2.6m and constant diameter 0.80 mm is made of steel with a Young modulus of 2.0 x 10^11 Pa. The wire is stretched so that its length increases by 1.2 mm. Assuming that the change is elastic, calculate for this wire:

1) The force applied at each end of the wire.

How would you do this?

I worked out the strain as being 4.62 x 10^-4 and the applied strain as being 92300000. Any ideas?
A wire of length 2.6m and constant diameter 0.80 mm is made of steel with a Young modulus of 2.0 x 10^11 Pa. The wire is stretched so that its length increases by 1.2 mm. Assuming that the change is elastic, calculate for this wire:

1) The force applied at each end of the wire.

How would you do this?

I worked out the strain as being 4.62 x 10^-4 and the applied strain as being 92300000. Any ideas?
Use Young Modulus = stress / strain
Stress is Force / Area of cross section
Strain = increase in length / original length

You can work out area of cross section from the diameter.
3. (Original post by Stonebridge)
Use Young Modulus = stress / strain
Stress is Force / Area of cross section
Strain = increase in length / original length

You can work out area of cross section from the diameter.
Right, so I would then just re-arrange the formula and do 92300000 x (0.0004^2 x Pi) = 46.4 N as the answer?
Right, so I would then just re-arrange the formula and do 92300000 x (0.0004^2 x Pi) = 46.4 N as the answer?
Yes, that's it.
5. (Original post by Stonebridge)
Yes, that's it.
Awesome thank you

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