What is the length of the copper wire? Physics with resistance?

Question

A uniform wire out of 0.800 g of copper. If the wire is to have a resistance R = 0.500 , and if all of the copper is to be used.
What will be the length of the wire?

Answer 1

To get the volume of Cu, multiply 0.8 by the density of Cu.

Volume of Cu = L * A,

where L is the length, A is the cross-section.

Also,

R = rho *L/A,

where R is the resistance, which you know, and rho is the resistivity.

You have two eqns with two unknowns. Solve for L.

Bozo

Answer 2

R= (rho) L/A (rho) = a million.7 x10^ (-8) ohm meter. R = 0.8 ohm. locate L/A L/A = R / (rho) = = 0. 8/ a million.7 x10^ (-8) = 4.71 x 10^7 m^ (-a million) ======================================... quantity of the cord = l. a. = Mass / density = a million.6x 10^ (-3) kg /8.92x10 ^3 kg*m^-3 =a million.seventy 9 x10^(-6) m^3 ======================================... Now multiply L/A and l. a. L/A * l. a. = L^2 = 4.71 x 10^7 *a million.seventy 9 x10^ (-6) = 80 4.48m^2 L = 9.2 m From l. a. = a million.seventy 9 x10^(-6) A = a million.seventy 9 x10^(-6)/ 9.2 A = a million.ninety 4 x 10^(-7) m^2 locate the diameter. ======================================