My calculations - youngs modulus

[jokiemay]

Im about to hand coursework in. Its the youngs modulus of copper wire

We added 100g weights and measured the extension using a traveling microscope.

for example at 0.900kg the wire extended by 6.36cm

my calculations are

Diameter = d 2.7x10-5 m
Cross section area A = Pi x d (squared) /4 = 5.7 x 10-8
Applied Force F = (mxg) 0.900 x 9.81 = 8.82 kg m s-1
Extension e = 0.0636 m
Original length L = 1.788 m

So Stress = F/A = 1.54 x 10(8)
Strain = E/L = 3.6 x 10-2

Stress / Strain = Youngs modulus E = 42 x 10(8) Pa

Does this look correct?

If i was to work out my mass / extension from my graph i would get this ...

m/e = 14.2 x (gxL) 17.5 / A 5.73 x 10-8 = 4.3 x 10(9) pa

 

[TaxOnFear]

Hi jokiemay,
I found it hard to understand what you're doing because you never really explained anything, you just have us a bunch of values. i.e. the cross-sectional area of what? What is 6.36cm? Is 0.9kg the mass of said object?

Help us to help you.

 

[jokiemay]

ive edited the post above . thanks

 

[jokiemay]

can anybody shine light on this ?

 

[asteriatic]

Your calculations and methodology seem to be correct. However, it is always a good idea to double check your calculations and make sure you have used the correct units throughout. Also, it would be helpful to include any sources or references that you used to determine the values of the constants used in your calculations. Overall, it seems like you have a good understanding of Young's modulus and have properly applied it to your experiment. Great job!