The Rate at which kinetic energy changes to thermal energy

AI Thread Summary
A potential difference of 50 mV across a 9.70 m wire with a cross-sectional area of 25.0 mm² and a conductivity of 6.80 x 10^6 (ohm.m)^-1 leads to a calculated power output of approximately 4.38 x 10^(-2) W. The resistivity was determined to be 1.471 x 10^(-7) ohm.m, and the resistance was calculated using the formula R = ρ (L/A). There was a noted error regarding the missing squared term in the power equation, and the final answer should be expressed in milliwatts or watts. Participants clarified that the energy transformation discussed is electric energy, not kinetic energy, although thermal energy can be viewed as kinetic at the atomic level. The discussion highlights the importance of unit consistency and correct terminology in physics calculations.
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A potential difference of 50 mV is maintained between the ends of a 9.70 m length of wire whose cross section area is 25.0mm^2. The conductivity of the wire is 6.80 x 10^6 (ohm.m)^-1. Determine the rate at which the energy in the wire is transformed into kinetic to thermal energy.

2. Homework Equations
P = v^2/R

ρ = 1/c

R = ρ (L/A)

Where ρ = resistivity
c = conductivity
A = area
L = length
R = Resistance
V = Voltage
P = power


3. The Attempt at a Solution

ρ = 1/6.80 x 10^6 = 1.471 x 10^(-7)

R = 1.471 x 10^(-7) * ( 9.70/0.000025 )
= 0.0570748
P = (50 x 10^-3)/0.0570748
= 0.0438021
= 4.38 x 10^(-2) W

This is my complete work. I think my workings are correct but My instructor says my answer is wrong. I will be glad if anyone can help.
 
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Where do you have kinetic energy? I think this should be electric energy.

There is a ^2 missing at P=, but the following line is correct. Units are missing everywhere :(.
I would express the final answer in mW or W. I agree with the result, however.
 
This is a duplicate of post https://www.physicsforums.com/showthread.php?t=685309, 1 hour earlier, apparently just to change the title.
As mfb says, there's is no kinetic energy involved here, unless you mean thermal energy viewed as kinetic at the atomic level.
 
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