Suppose that you wish to fabricate a uniform wire out of 0.900 g of copper. If the wire is to have a resistance R = 0.700 ohm, and if all of the copper is to be used.
(a) What will be the length of the wire? M
R = pL/A
R = .700 ohm and p = 1.7 x 10^-8
The Attempt at a Solution
first thing i did was input the given number
.700 = (1.7x10^-8)L/A
my main problem is finding A with the given weight of copper, but this is what i did.
n = m/M = .900/63.54 = .0142 then,
.0142(6.02x10^23) = 8.53 x 10^21
this is where i get lost because to get A its A = DeltaQ/DeltaT but time was never a given and i believe its not needed.
(8.53 x 10^21) x (1.6 x 10^-19) = 1364.8
I know there are other ways to get "A" by A = DeltaV/R but Volts were never given.
Any help on this would be great.