How do I calculate the length required?

Question

A 47g sample of a conducting material is all that is available. The resistivity of the material is measured to be 1.2x10^-7 Ohm-meter, and the density is 8.12g/cm^3. The material is to be shaped into a solid cylindrical wire that has a total resistance of 1.5 Ohms. What is the length required in meters?

Answer 1

Volume = mass/density = 5.788 cm^3
Volume = Areawire * Lwire
Rbulk = 1.2E-7 ohm-m = 1.2E-5 ohm-cm
Rbulk = Rwire * Areawire / Lwire
Rbulk/Volume = Rwire / Lwire^2
Lwire = sqrt(Rwire * Volume / Rbulk)
Answer will be in cm.