Electron travel in a wire; distance

Click For Summary
SUMMARY

The discussion centers on calculating the distance an electron travels in a copper wire while a starter motor draws a current of 140 A for 0.95 seconds. The wire has a diameter of 5.0 mm and a length of 1.2 m. The user correctly calculated the charge passing through the motor as 133 Coulombs and the current density as 7,130,141.45 A/m². To find the distance traveled by an electron, the drift velocity formula must be applied, utilizing the current density and the concentration of charge carriers in copper.

PREREQUISITES
  • Understanding of drift velocity in conductors
  • Knowledge of current density calculations
  • Familiarity with elementary charge and charge carrier concentration
  • Basic principles of electric current and charge flow
NEXT STEPS
  • Learn how to calculate drift velocity using the formula: drift velocity = current density / (elementary charge * charge carrier concentration)
  • Research the properties of copper, including charge carrier concentration
  • Study the relationship between current, charge, and time in electrical circuits
  • Explore practical applications of drift velocity in electrical engineering
USEFUL FOR

Students studying physics, electrical engineers, and anyone interested in understanding electron movement in conductive materials.

megr_ftw
Messages
68
Reaction score
0

Homework Statement


The starter motor of a car engine draws a current of 140 A from the battery. The copper wire to the motor is 5.0 mm in diameter and 1.2 m long. The starter motor runs for 0.95 s until the car engine starts.

How far does an electron travel along the wire while the starter motor is on?



Homework Equations


drift velocity= (j) / (en)
j= current density, e=elementary charge, n=concentration of gases in material(given in book)

j= I/A

The Attempt at a Solution


I found the charge that passes through the starter motor to be 133 Coulombs. Am I suppose to incorporate the equation for drift velocity in order to find the distance?
 
Physics news on Phys.org
and I actually just found the current density to be 7130141.45 A/m^2 using the second equation.
now, how am I suppose to go from this to the distance the electron travels after 0.95 seconds??
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
7K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
6K
  • · Replies 7 ·
Replies
7
Views
2K
Replies
1
Views
2K
  • · Replies 13 ·
Replies
13
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
Replies
1
Views
10K
  • · Replies 1 ·
Replies
1
Views
11K
  • · Replies 8 ·
Replies
8
Views
2K