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Ch 23: Electric Potential
Young & Freedman Calc - University Physics 14th Edition
Young & Freedman Calc14th EditionUniversity PhysicsISBN: 9780321973610Not the one you use?Change textbook
Chapter 23, Problem 19b

Two point charges q1=+2.40q_1 = +2.40 nC and q2=6.50q_2 = -6.50 nC are 0.1000.100 m apart. Point AA is midway between them; point BB is 0.0800.080 m from q1q_1 and 0.0600.060 m from q2q_2 (Fig. E23.1923.19). Take the electric potential to be zero at infinity. Find the potential at point BB.
Diagram showing two point charges, q1 and q2, with distances to points A and B for electric potential calculation.

Verified step by step guidance
1
Identify the charges and their positions: q_1 = +2.40 nC, q_2 = -6.50 nC. Point B is 0.080 m from q_1 and 0.060 m from q_2.
Recall the formula for electric potential V due to a point charge: V = k * q / r, where k is Coulomb's constant (8.99 x 10^9 N m²/C²), q is the charge, and r is the distance from the charge.
Calculate the potential at point B due to q_1 using the formula V_1 = k * q_1 / r_1, where r_1 = 0.080 m.
Calculate the potential at point B due to q_2 using the formula V_2 = k * q_2 / r_2, where r_2 = 0.060 m.
Find the total electric potential at point B by summing the potentials from both charges: V_B = V_1 + V_2.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Electric Potential

Electric potential, or voltage, is the amount of electric potential energy per unit charge at a point in an electric field. It is a scalar quantity measured in volts (V) and indicates the work done to move a charge from a reference point (often infinity) to a specific point in the field. The potential due to a point charge is given by the formula V = k * q / r, where k is Coulomb's constant, q is the charge, and r is the distance from the charge.
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Superposition Principle

The superposition principle states that the total electric potential at a point due to multiple point charges is the algebraic sum of the potentials due to each charge individually. This means that when calculating the potential at a point, one can consider the contributions from each charge separately and then add them together, taking into account their signs (positive or negative) and distances from the point of interest.
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Coulomb's Law

Coulomb's Law describes the force between two point charges. It states that the electric force (F) between two charges is directly proportional to the product of the magnitudes of the charges (q1 and q2) and inversely proportional to the square of the distance (r) between them. The law is mathematically expressed as F = k * |q1 * q2| / r², where k is Coulomb's constant. This principle underlies the interactions that lead to the electric potential in a system of charges.
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Related Practice
Textbook Question

Two point charges of equal magnitude QQ are held a distance dd apart. Consider only points on the line passing through both charges. If the two charges have the same sign, find the location of all points (if there are any) at which (i) the potential (relative to infinity) is zero (is the electric field zero at these points?), and (ii) the electric field is zero (is the potential zero at these points?).

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Textbook Question

At a certain distance from a point charge, the potential and electric-field magnitude due to that charge are 4.984.98 V and 16.216.2 V/m, respectively. (Take V=0V = 0 at infinity.) What is the distance to the point charge?

Textbook Question

An electron is to be accelerated from 3.00×1063.00\(\times\)10^6 m/s to 8.00×1068.00\(\times\)10^6 m/s. Through what potential difference must the electron pass to accomplish this?

Textbook Question

Two point charges q1=+2.40q_1 = +2.40 nC and q2=6.50q_2 = -6.50 nC are 0.1000.100 m apart. Point AA is midway between them; point BB is 0.0800.080 m from q1q_1 and 0.0600.060 m from q2q_2 (Fig. E23.1923.19). Take the electric potential to be zero at infinity. Find the potential at point AA.

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Textbook Question

At a certain distance from a point charge, the potential and electric-field magnitude due to that charge are 4.984.98 V and 16.216.2 V/m, respectively. (Take V=0V = 0 at infinity.) What is the magnitude of the charge?

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Textbook Question

Point charges q1=+2.00q_1 = +2.00 μμC and q2=2.00q_2 = -2.00 μμC are placed at adjacent corners of a square for which the length of each side is 3.003.00 cm. Point aa is at the center of the square, and point bb is at the empty corner closest to q2q_2q2q_2. Take the electric potential to be zero at a distance far from both charges. (a) What is the electric potential at point a due to q1q_1 and q2q_2?

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