Both wires are made up of the same material which means they will have the same young modulus.
Y = F/A × L/ΔL
From the equation above, the force applied per cross sectional (same diameter) are is the same for both materials and is constant.
So
L1/ΔL1 = L2/ΔL2
Or L2/L1 = ΔL2/ΔL1
So the force needed to bring about a stretching the the breaking point is the same. The only difference is in by how much the longer wire would have to stretch before reaching its breaking point.
Yes that is correct. We know this because 4.00 x 10 4 Pa is constant. If you have 2.00×10−3m3 then you do the following: (2.00×10^−3)(4.00×10^<span> 4) = </span>8.00×10^−3. That is how you get your answer