# Young's modulus problem

1. Jul 22, 2008

### ACCC12

hi

i have been given these results in order to work out the young's modulus can any 1 tell me how i go about doin this

Force (kN) Extension (mm)
0.5 0.003
1 0.011
1.5 0.019
2 0.021
2.5 0.024
3 0.032
3.5 0.040
4 0.043
4.5 0.050
5 0.060
5.5 0.064
6 0.070
6.5 0.076
7 0.081

Area 50mm by 5

2. Jul 22, 2008

### rock.freak667

$$E=\frac{stress}{strain}$$

Write the formula for stress and the formula fopr strain and then simply the formula for Young's Modulus,E.

3. Jul 26, 2008

### ACCC12

i know the equation but i didnt know which part of the data to use, do i just take any part of the data from the table or do i have to plot a graph! thanks for all ya help!

4. Jul 27, 2008

### dk_ch

what is meant by "area 50mm by 5 " in your data ? please explain.

5. Jul 28, 2008

### rock.freak667

$$E=\frac{\frac{F}{A}}{\frac{e}{l}}$$

$$E=\frac{Fl}{Ae}$$

Right?

From your graph, what does the fraction F/e represent?

6. Jul 29, 2008

### ACCC12

50mm length, 5mm diameter

7. Jul 29, 2008

### ACCC12

got the answer to be 5.3 is that correct!

equation used

2.5 x 50
----------
981.75 x 0.024

8. Aug 3, 2008

### ACCC12

any takers! thanks