Solving for Work in a Stressed Aluminum Wire: Figure 12-56 Example

[slydg895]

hey guys i have tried this problem many times and can't figure out the answer. please help

Heres the problem:
Figure 12-56 shows the stress versus strain plot for an aluminum wire that is stretched by a machine pulling in opposite directions at the two ends of the wire. The scale of the stress axis is set by s = 5.50, in units of 10^7 N/m2. The wire has an initial length of 0.950 m and an initial cross-sectional area of 2.50 × 10^-6 m2. How much work does the force from the machine do on the wire to produce a strain of 1.90 × 10^-3?

This is my work:
W=.5(stress)(strain)(volume)
volume=(area)(lenght)
And i get .124094.

What am i doing wrong?

 

[slydg895]

Does anyone have any ideas?

 

[PhanthomJay]

Does anyone have any ideas?

It is unclear what is the Elasticity modulus or the slope of the stress - strain curve or the value of the strain at the given stress? You didn't attach a figure.

 

[Squeeg]

I have a similar problem, my elasticity modulus (stress/strain) = 7E10.

 

[asteriatic]

As a scientist, it is important to approach problems with a systematic and analytical mindset. It seems that you have attempted to solve the problem using the equation W=.5(stress)(strain)(volume), which is a good starting point. However, it is important to make sure that all of your units are consistent and that you have the correct values for each variable.

In this case, it seems like you have the correct values for stress and strain, but the units for stress should be in N/m^2, not 10^7 N/m^2. Additionally, it is important to double check your calculations to ensure that you are using the correct values for the area and length of the wire.

In order to solve for work, you can use the equation W = FΔx, where F is the force and Δx is the displacement. In this case, the force can be calculated using the stress and area of the wire, and the displacement can be calculated using the initial length of the wire and the strain.

I recommend going back through your calculations and double checking your units and values. If you are still having trouble, it may be helpful to ask a classmate or teacher for assistance. Remember to approach problems with a logical and systematic approach, and don't be afraid to ask for help when needed.