4.A plastic rod with a uniform charge -Q is bent in a 120° circular arc of radius r and symmetrically paced across an x axis with the origin at the center of curvature P of the rod. In terms of Q and r, what is the electric field E due to the rod at point P? ( E as a function of K, Q and r)

College Physics
11th Edition
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Raymond A. Serway, Chris Vuille
Chapter1: Units, Trigonometry. And Vectors
Section: Chapter Questions
Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...
icon
Related questions
Question
### Question 4: Electric Field Due to a Charged Rod

**Problem Statement:**

A plastic rod with a uniform charge -Q is bent in a 120° circular arc of radius \( r \) and symmetrically placed across an x-axis with the origin at the center of curvature \( P \) of the rod. In terms of \( Q \) and \( r \), what is the electric field \( \vec{E} \) due to the rod at point \( P \)? (Express \( \vec{E} \) as a function of \( K \), \( Q \), and \( r \)).

**Explanation:**

- A plastic rod is uniformly charged with a negative charge \(-Q\).
- The rod is shaped into a circular arc covering 120 degrees.
- The radius of this arc is \( r \).
- The arc is positioned such that it is symmetric around the x-axis.
- The origin (\( O \)) is at the center of curvature of the arc.
- We aim to find the electric field \( \vec{E} \) at point \( P \), which is at the center of curvature, in terms of the constants \( K \), \( Q \), and \( r \).

#### Notable Variables:
- \( Q \): Total charge on the rod.
- \( r \): Radius of the circular arc.
- \( K \): Coulomb's constant.

**Detailed Solution**

Given that the charge is uniformly distributed along the arc, we can calculate the linear charge density \( \lambda \) (charge per unit length):

\[ \lambda = \frac{Q}{L} \]

where \( L \) is the length of the arc. The length of the arc can be calculated as:

\[ L = r \cdot \theta \]
where \( \theta \) is the angle in radians. For a 120° arc, we convert degrees to radians:

\[ \theta = \frac{120^\circ}{180^\circ} \pi = \frac{2\pi}{3} \]

Thus:

\[ L = r \cdot \frac{2\pi}{3} = \frac{2\pi r}{3} \]

Therefore, the linear charge density \( \lambda \) is:

\[ \lambda = \frac{-Q}{\frac{2\pi r}{3}} = \frac{-3Q}{2\pi
Transcribed Image Text:### Question 4: Electric Field Due to a Charged Rod **Problem Statement:** A plastic rod with a uniform charge -Q is bent in a 120° circular arc of radius \( r \) and symmetrically placed across an x-axis with the origin at the center of curvature \( P \) of the rod. In terms of \( Q \) and \( r \), what is the electric field \( \vec{E} \) due to the rod at point \( P \)? (Express \( \vec{E} \) as a function of \( K \), \( Q \), and \( r \)). **Explanation:** - A plastic rod is uniformly charged with a negative charge \(-Q\). - The rod is shaped into a circular arc covering 120 degrees. - The radius of this arc is \( r \). - The arc is positioned such that it is symmetric around the x-axis. - The origin (\( O \)) is at the center of curvature of the arc. - We aim to find the electric field \( \vec{E} \) at point \( P \), which is at the center of curvature, in terms of the constants \( K \), \( Q \), and \( r \). #### Notable Variables: - \( Q \): Total charge on the rod. - \( r \): Radius of the circular arc. - \( K \): Coulomb's constant. **Detailed Solution** Given that the charge is uniformly distributed along the arc, we can calculate the linear charge density \( \lambda \) (charge per unit length): \[ \lambda = \frac{Q}{L} \] where \( L \) is the length of the arc. The length of the arc can be calculated as: \[ L = r \cdot \theta \] where \( \theta \) is the angle in radians. For a 120° arc, we convert degrees to radians: \[ \theta = \frac{120^\circ}{180^\circ} \pi = \frac{2\pi}{3} \] Thus: \[ L = r \cdot \frac{2\pi}{3} = \frac{2\pi r}{3} \] Therefore, the linear charge density \( \lambda \) is: \[ \lambda = \frac{-Q}{\frac{2\pi r}{3}} = \frac{-3Q}{2\pi
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 4 steps with 6 images

Blurred answer
Knowledge Booster
Electric field
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
College Physics
College Physics
Physics
ISBN:
9781305952300
Author:
Raymond A. Serway, Chris Vuille
Publisher:
Cengage Learning
University Physics (14th Edition)
University Physics (14th Edition)
Physics
ISBN:
9780133969290
Author:
Hugh D. Young, Roger A. Freedman
Publisher:
PEARSON
Introduction To Quantum Mechanics
Introduction To Quantum Mechanics
Physics
ISBN:
9781107189638
Author:
Griffiths, David J., Schroeter, Darrell F.
Publisher:
Cambridge University Press
Physics for Scientists and Engineers
Physics for Scientists and Engineers
Physics
ISBN:
9781337553278
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
Lecture- Tutorials for Introductory Astronomy
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:
9780321820464
Author:
Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:
Addison-Wesley
College Physics: A Strategic Approach (4th Editio…
College Physics: A Strategic Approach (4th Editio…
Physics
ISBN:
9780134609034
Author:
Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:
PEARSON