The Rate at which kinetic energy changes to thermal energy

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SUMMARY

The discussion centers on calculating the rate at which electrical energy transforms into thermal energy in a wire with a potential difference of 50 mV, a length of 9.70 m, and a cross-sectional area of 25.0 mm². The conductivity of the wire is given as 6.80 x 106 (ohm.m)-1. The resistance is calculated using the formula R = ρ (L/A), resulting in R = 0.0570748 ohms, leading to a power dissipation of approximately 4.38 x 10-2 W. The discussion clarifies that the energy transformation in question is thermal, not kinetic, as initially suggested by the poster.

PREREQUISITES
  • Understanding of electrical resistance and conductivity
  • Familiarity with the formula for power (P = V²/R)
  • Knowledge of resistivity and its relationship to conductivity
  • Basic principles of energy transformation in electrical systems
NEXT STEPS
  • Study the concept of electrical power dissipation in resistive materials
  • Learn about the relationship between thermal energy and atomic kinetic energy
  • Explore advanced topics in electrical conductivity and resistivity
  • Investigate practical applications of thermal energy conversion in electrical systems
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This discussion is beneficial for electrical engineers, physics students, and anyone interested in understanding the principles of energy transformation in conductive materials.

Pruddy
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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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