/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 37 What is the magnitude of the ele... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

What is the magnitude of the electric field at the point \((3.00 \hat{i}-2.00 \hat{j}+4.00 \hat{k}) \mathrm{m}\) if the electric potential in the region is given by \(V=2.00 x y z^{2}\), where \(V\) is in volts and coordinates \(x, y\), and \(z\) are in meters?

Short Answer

Expert verified
The magnitude of the electric field is approximately 150 V/m.

Step by step solution

01

Understand the Problem

We're tasked with finding the electric field's magnitude at a given point, given the potential function \(V = 2.00 x y z^2\). The electric field \(\mathbf{E}\) is related to the potential \(V\) by \(\mathbf{E} = -abla V\).
02

Calculate the Gradient of the Potential

Calculate each partial derivative of \(V\):- \(\frac{\partial V}{\partial x} = 2.00 y z^2\)- \(\frac{\partial V}{\partial y} = 2.00 x z^2\)- \(\frac{\partial V}{\partial z} = 4.00 x y z\)Thus, \(abla V = (2.00 y z^2)\hat{i} + (2.00 x z^2)\hat{j} + (4.00 x y z)\hat{k}\).
03

Evaluate the Gradient at the Given Point

Substitute \(x = 3.00\), \(y = -2.00\), and \(z = 4.00\) into the gradient:- \(\frac{\partial V}{\partial x}|_{(3,-2,4)} = 2.00(-2.00)(4.00)^2 = -64\)- \(\frac{\partial V}{\partial y}|_{(3,-2,4)} = 2.00(3.00)(4.00)^2 = 96\)- \(\frac{\partial V}{\partial z}|_{(3,-2,4)} = 4.00(3.00)(-2.00)(4.00) = -96\)So, \(abla V|_{(3,-2,4)} = -64\hat{i} + 96\hat{j} - 96\hat{k}\).
04

Determine the Electric Field

The electric field \(\mathbf{E}\) is the negative of the gradient of \(V\):\[\mathbf{E} = -(-64\hat{i} + 96\hat{j} - 96\hat{k}) = 64\hat{i} - 96\hat{j} + 96\hat{k}\]\.
05

Calculate the Magnitude of the Electric Field

The magnitude of \(\mathbf{E}\) is given by:\[|\mathbf{E}| = \sqrt{(64)^2 + (-96)^2 + (96)^2}\]Calculate:- \(64^2 = 4096\)- \((-96)^2 = 9216\)- \((96)^2 = 9216\)Thus, \(|\mathbf{E}| = \sqrt{4096 + 9216 + 9216} = \sqrt{22528} \approx 150\) V/m.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Electric Potential
Electric potential is an important concept in physics that describes the potential energy per unit charge at a point in an electric field. It's a scalar quantity, often denoted by the symbol \(V\) and measured in volts (V). In this exercise, the electric potential is given by the function \(V = 2.00 x y z^2\). This function indicates how the potential varies with the coordinates \(x\), \(y\), and \(z\).

Understanding electric potential helps in determining how charged particles move within an electric field. A charge will naturally move from a region of higher potential to lower potential, much like a ball rolling downhill.
  • Higher electric potential often means more potential energy.
  • A positive test charge loses potential energy by moving from a higher to a lower potential area.
  • This loss of potential energy is related to work done by or against electric forces.
Knowing the electric potential at a specific point gives insight into the work needed to move a charge to that point from a reference location.
Gradient Calculation
Gradient calculation is essential in understanding how the electric potential changes in space. The gradient of a scalar field, like potential \(V\), results in a vector field. This process is known as taking the derivative of the potential with respect to each spatial coordinate, resulting in partial derivatives.

For our problem, we find the gradient of the potential function \(V = 2.00 x y z^2\):
  • \(\frac{\partial V}{\partial x} = 2.00 y z^2\)
  • \(\frac{\partial V}{\partial y} = 2.00 x z^2\)
  • \(\frac{\partial V}{\partial z} = 4.00 x y z\)
The gradient vector \(abla V\) is a vector that points in the direction of the greatest rate of increase of the function, and its magnitude is the maximum rate of increase. For our three-dimensional space, the gradient is expressed as:
\[abla V = (2.00 y z^2)\hat{i} + (2.00 x z^2)\hat{j} + (4.00 x y z)\hat{k}\]Calculating gradients helps interpret the behavior of scalar fields in vector form, giving deeper insights into physical phenomena like electric fields.
Vector Calculus
Vector calculus is a branch of mathematics focused on vector fields, involving differential and integral operators. It plays a crucial role in electromagnetism, including the study of electric and magnetic fields.

In this problem, vector calculus helps us understand how to derive the electric field from the electric potential. By calculating the gradient, as demonstrated previously, we use a fundamental vector calculus operation to transition from potential (a scalar field) to electric field (a vector field).
  • The gradient operator \(abla\) represents one of the key differential operations in vector calculus.
  • Other operators in vector calculus include divergence and curl, each providing different insights into vector field behavior.
  • Understanding these ideas helps interpret physical phenomena more comprehensively.
Those foundational elements allow scientists and engineers to explore the nature of electric and magnetic interactions comprehensively, aiding in various applications from designing circuits to exploring fundamental physics principles.
Electric Field Magnitude
The electric field magnitude indicates the strength of the electric field at a particular point. It's obtained from the electric field vector \(\mathbf{E}\) by calculating its magnitude using the Pythagorean theorem in three-dimensional space.

In our problem, once we determine the electric field vector \(\mathbf{E} = 64\hat{i} - 96\hat{j} + 96\hat{k}\), the next step is finding its magnitude:
  • Use the formula: \(|\mathbf{E}| = \sqrt{(E_x)^2 + (E_y)^2 + (E_z)^2}\) where \(E_x\), \(E_y\), and \(E_z\) are components of \(\mathbf{E}\).
  • In our case, calculate each squared component: \(64^2\), \((-96)^2\), \(96^2\).
  • Sum and take the square root: \(|\mathbf{E}| = \sqrt{4096 + 9216 + 9216} = \sqrt{22528}\).
  • Resulting in an approximate value of about \(150\) V/m.
The magnitude provides a single scalar value conveying the field's strength and enables comparisons between different field intensities at different points.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

(a) If Earth had a uniform surface charge density of \(1.0\) electron \(/ \mathrm{m}^{2}\) (a very artificial assumption), what would its potential be? (Set \(V=0\) at infinity.) What would be the (b) magnitude and (c) direction (radially inward or outward) of the electric field due to Earth just outside its surface?

(a) What is the electric potential energy of two electrons separated by \(2.00 \mathrm{~nm} ?\) (b) If the separation increases, does the potential energy increase or decrease?

Two metal spheres, each of radius \(3.0 \mathrm{~cm}\), have a center-to-center separation of \(2.0 \mathrm{~m} .\) Sphere 1 has charge \(+1.0 \times\) \(10^{-8} \mathrm{C}\); sphere 2 has charge \(-3.0 \times 10^{-8} \mathrm{C}\). Assume that the separation is large enough for us to say that the charge on each sphere is uniformly distributed (the spheres do not affect each other). With \(V=0\) at infinity, calculate (a) the potential at the point halfway between the centers and the potential on the surface of (b) sphere 1 and \((\mathrm{c})\) sphere \(2 .\)

Suppose that in a lightning flash the potential difference between a cloud and the ground is \(1.0 \times 10^{9} \mathrm{~V}\) and the quantity of charge transferred is \(30 \mathrm{C}\). (a) What is the change in energy of that transferred charge? (b) If all the energy released could be used to accelerate a \(1000 \mathrm{~kg}\) car from rest, what would be its final speed?

A nonuniform linear charge distribution given by \(\lambda=\) \(b x\), where \(b\) is a constant, is located along an \(x\) axis from \(x=0\) to \(x=0.20 \mathrm{~m}\). If \(b=20 \mathrm{nC} / \mathrm{m}^{2}\) and \(V=0\) at infinity, what is the electric potential at (a) the origin and (b) the point \(y=0.15 \mathrm{~m}\) on the \(y\) axis?

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.