ok...so here's the problem: A wire of initial length L0 and radius r0 has a measured resistance of 1.5 . The wire is drawn under tensile stress to a new uniform radius of r = 0.50r0. What is the new resistance of the wire?



I know the equation for it is R (1.5) = pLo/pi*ro^2 so the equation for the new wire is R1 = pLo/pi*.5ro^2 but I can't seem to get it right. Can any point me in the right direction? Thanks!

7/24/2006 5:39:20 PM

i hope youve taken into acount special relativity

7/24/2006 6:07:34 PM

i think your mistake is that the new equation is not R1 = pLo/pi*.5ro^2 but is R1 = pLo/pi*(.5)^2*ro^2 the 0.5 * R0 is a quantity so you have (0.5 * R0) = 0.25 * R0. Once you do this, just solve for 1.5 = pLo/pi*(0.5 * R0)^2 and you should have your answer.

7/24/2006 6:30:23 PM

F=ma

7/25/2006 2:15:39 PM