need some help: electrician questions

[pyro]

im doing a couple practice problems and theres a couple questions that i cant seem to figure out, any help would be good

1. A #12 conductor has a cross sectional area of 3.31 mm² and a resistance of 5.01Ω per 1000m at 0°C

a) estimate the cross sectional area and resistance of 250m of #8 copper conductor at 0°C
b)estimate the cross sectional area and resistance of 400m of #14 copper conductor at 0°C

2. 80m of #12 copper conductor at 60°C. determine the cross sectional area and the resistance?

[frostyda9]

Why are they asking you to estimate the cross sectional area? These are physical properties that are listed in the tables in the code book. Are they being so precise that you are trying to estimate the deviation from the published values due to the expansion or contraction of the conductors in different ambient temperature situations?

[pyro]

ya im pretty sure thats what there asking like for the first question i think i have to use R2=R1(1+temp coefficiant(T2-T1)) so the temp coefficiant for copper would be 0.0039 but i have to find the resistance for R1 first, so i think i have to use R=Pl/A . i dont know for sure though