The Rate at which kinetic energy changes to thermal energy

In summary, a potential difference of 50 mV is maintained across a 9.70 m wire with a cross section area of 25.0 mm^2 and a conductivity of 6.80 x 10^6 (ohm.m)^-1, resulting in a power of 4.38 x 10^-2 W.
  • #1
Pruddy
64
0
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.
 
Physics news on Phys.org
  • #2
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.
 
  • #3
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.
 

Related to The Rate at which kinetic energy changes to thermal energy

What is kinetic energy?

Kinetic energy is the energy that an object possesses due to its motion. It is calculated by multiplying the mass of the object by the square of its velocity.

What is thermal energy?

Thermal energy is the energy that an object possesses due to the motion of its particles. It is a form of kinetic energy that is associated with the random motion of atoms and molecules within a substance.

How does kinetic energy change to thermal energy?

When an object with kinetic energy comes into contact with another object or its surroundings, some of its kinetic energy is transferred in the form of heat. This causes the particles of the object to vibrate faster, increasing their thermal energy.

What factors affect the rate at which kinetic energy changes to thermal energy?

The rate at which kinetic energy changes to thermal energy depends on factors such as the mass and velocity of the object, the temperature difference between the object and its surroundings, and the material properties of the objects involved.

Why is it important to understand the rate at which kinetic energy changes to thermal energy?

Understanding this rate is important because it helps us to predict and control the effects of energy transfer on different objects and systems. It also plays a crucial role in various fields of science and engineering, such as thermodynamics, heat transfer, and materials science.

Similar threads

  • Introductory Physics Homework Help
Replies
4
Views
2K
  • Introductory Physics Homework Help
2
Replies
38
Views
2K
  • Introductory Physics Homework Help
Replies
6
Views
683
  • Introductory Physics Homework Help
2
Replies
54
Views
8K
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
761
  • Introductory Physics Homework Help
Replies
1
Views
4K
  • Introductory Physics Homework Help
Replies
12
Views
2K
  • Introductory Physics Homework Help
Replies
13
Views
2K
  • Introductory Physics Homework Help
Replies
23
Views
2K
Back
Top