structures and materials help please

[methodsboy]

hi
im kinda puzzled on these two questions:

2009 checkpoints:
question 530 pg 109.
Calculate the Young's Modulus for a Hookean rope of length 30m, cross sectional area = 30cm^2, which stretches 2m under a load of 1000N.
I keep getting 49751 which is approx. 5 x 10^4, answers states that it is 5 x 10^6 

question 534 pg 110.
Young's Modulus for material A = approx. 2.5 x 10^12. It is shaped into a square of cross-section of side 5cm and length 2m. Calculate the tensile strength of the material.
(note : you may need to refer to the graph in question 532)

It would be great if anyone can answer these questions 

[iamdan08]

For the first question, are you converting the cross sectional area to m^2 (/100^2), because when i do that i get the answer the book does...

[methodsboy]

30cm^2= 0.3m^2
stress = 1000/0.3 = 3333.33333
strain = 2/30 = 0.067

Young's Modulus = 3333.3333/0.067 = 49751???

[iamdan08]

When you convert to you divide by 100^2

[methodsboy]

When you convert to you devide by 100^2

are u sure?
up to now, i've been doing /100

[iamdan08]

Yeah i'm sure. You might have been converting the radius the way you did previously, which would be correct, but when converting area squared you have to do the way i have done.

[methodsboy]

oh ok. Thanks.

[danieltennis]