Question 1

Two electrons are passing 26.0 mm apart.What is the electric repulsive force that they exert on each other? (The value of k is 9.0 × 10⁹ N·m²/C². ) A)3.4 × 10^-25 N B)1.3 × 10¹⁰ N C)1.3 N D)3.4 × 10^-27 N

Accepted Answer

The electric force between two charges is given by Coulomb's law: F = k * |q1 * q2| / r^2. For two electrons, q1 = q2 = -1.6 × 10^-19 C, and r = 26.0 mm = 0.026 m. Substituting these values into the formula gives F ≈ 3.4 × 10^-25 N.

Question 2

The charge in the bottom right corner of the figure is Q =- 45 nC.What is the magnitude of the force on Q? A)1.9 × 10^-2 N B)1.4 × 10^-2N C)2.6 × 10^-2 N D)3.5 × 10^-2 N

Accepted Answer

A

Question 3

Three charges of magnitude 3.0 $\times$ 10^-4 C each are located at x = 1.0 m,y = 1.0 m,at s = 0.0 m,y = 0.0 m,and at x = -1.0 m,y = 0.0 m.The one in the middle is negative,while the other two are positive.What is the net Coulombic force exerted by them on a negative 3.0 $\times$ 10^-5 C charge located at x = 0.0 m,y = 2.0 m? (The value of k is 9.0 × 10⁹ N·m²/C². ) A)87 N attractive B)87 N repulsive C)120 N attractive D)120 N repulsive

Accepted Answer

The net force is attractive because the negative charge at the origin is attracted to the positive charges and repelled by the negative charge, resulting in a net attractive force.

Question 4

A metal sphere is insulated electrically and is given a charge.If 25 electrons are added to the sphere in giving a charge,how many Coulombs are added to the sphere?
A)- 4.0 × 10-18 C
B)- 4.0 × 10-20 C
C)- 40 C
D)- 25 C

Accepted Answer

The charge of one electron is approximately -1.6 × 10^-19 C. Therefore, the total charge added by 25 electrons is 25 × (-1.6 × 10^-19 C) = -4.0 × 10^-18 C.

Question 5

The charge at the bottom of the figure is Q = + 17 nC.What is the magnitude of the force on the charge Q? A)1.9 × 10^-4N B)1.2 × 10^-4N C)1.6 × 10^-4 N D)2.3 × 10^-4 N

Accepted Answer

The answer of The charge at the bottom of the...

Question 6

An asteroid has acquired a net charge of 105 C from being bombarded by the solar wind over the years,and is currently in equilibrium whereby it expels electrons at the same rate as it acquires them.How many more electrons does it have than protons? A)6.56 × 10²⁰ B)656 C)630 D)1.05 × 10^-17

Accepted Answer

The charge of an electron is approximately -1.6 × 10^-19 C. To find the number of excess electrons, divide the total charge by the charge of one electron: 105 C / 1.6 × 10^-19 C/electron ≈ 6.56 × 10^20 electrons.

Question 7

An asteroid of mass 58,000 kg carrying a negative charge of 15.0 μC is 180 m from a second asteroid of mass 52,000 kg carrying a negative charge of 11.0 μC .What is the net force the asteroids exert upon each other? (G = 6.673 × 10^-11 N·m²/kg² and k = 9.0 × 10⁹ N·m²/C². ) A)0.000040 N B)0.0062 N C)570,000 N D)510,000 N

Accepted Answer

The gravitational force is attractive and calculated using Newton's law of universal gravitation, while the electrostatic force is repulsive (since both charges are negative) and calculated using Coulomb's law. The gravitational force is much smaller than the electrostatic force, resulting in a net force close to zero.

Question 8

Two like charges of the same magnitude are 5.0 mm apart.If the force of repulsion they exert upon each other is 2.0 N,what is the magnitude of each charge? (The constant of proportionality for the Coulombic force is 9.0 × 10⁹ N·m²/C². ) A)7.5 × 10^-2 C B)7.5 × 10^-8 C C)7.2 × 10² C D)7.5 × 10^-5 C

Accepted Answer

Using Coulomb's law, F = k * (q1 * q2) / r^2, where F = 2.0 N, k = 9.0 × 10^9 N·m^2/C^2, and r = 5.0 mm = 5.0 × 10^-3 m. Solving for q (since q1 = q2), we get q = sqrt((F * r^2) / k) = sqrt((2.0 * (5.0 × 10^-3)^2) / (9.0 × 10^9)) = 7.5 × 10^-8 C.

Question 9

A 3.0 μC positive charge is located at the origin and a 2.0 μC positive charge is located at x = 0.0 m,y = 1.0 m.Find the point between them where the electric field strength is zero.
A)x = 0 m,y = 0.55 m
B)x = 0 m,y = 0.67 m
C)x = 0 m,y = 1.5 m
D)x = 0 m,y = 0.60 m

Accepted Answer

The electric field strength is zero at the point where the electric fields due to the two charges cancel each other out. This occurs at a point on the x-axis, where the distance from the 3.0 μC charge is 3/5 of the distance from the 2.0 μC charge. Therefore, the point is at x = 0 m, y = 0.6 m.

Question 10

A small glass bead has been charged to 8.0 nC? What is the strength of the electric field 2.0 cm from the center of the bead? A)1.8 × 10⁵ N/C B)3.6 × 10³ N/C C)1.4 × 10^-3 N/C D)3.6 × 10^-6 N/C

Accepted Answer

The electric field (E) due to a point charge is given by the formula E = k * |q| / r², where k is Coulomb's constant (8.99 × 10^9 N·m²/C²), q is the charge (8.0 nC = 8.0 × 10^-9 C), and r is the distance (0.02 m). Plugging in these values gives E = (8.99 × 10^9) * (8.0 × 10^-9) / (0.02)² = 1.8 × 10^5 N/C.

Question 11

Two equally charged spheres of mass 1.0 g are placed 2.0 cm apart.When released,they begin to accelerate at 414 m/s².What is the magnitude of the charge on each sphere? A)140 nC B)120 nC C)95 nC D)75 nC

Accepted Answer

The force between the spheres is given by F = ma = 1.0 g * 414 m/s² = 0.414 N. Using Coulomb's law, F = k * q² / r², where k = 8.99 x 10^9 N m²/C² and r = 0.02 m. Solving for q gives q ≈ 140 nC.

Question 12

The electric field 2.8 cm from a small object points toward the object with a strength of 180,000 N/C.What is the object's charge?
A)- 16 nC
B)+ 16 nC
C)- 17 nC
D)+ 17 nC

Accepted Answer

The electric field points toward the object, indicating a negative charge. Using the formula E = k|q|/r^2, where E is the electric field, k is Coulomb's constant (8.99 x 10^9 N m^2/C^2), and r is the distance (0.028 m), solving for q gives approximately -16 nC.

Question 13

A small piece of aluminum (atomic number 13)contains 1015 atoms.(The atomic number is the number of protons;it determines the (positive)electric charge of the nucleus and,thus,the number of electrons in a neutral atom. )If the piece of aluminum has a net positive charge of 3.0 μC,what fraction of the electrons that the aluminum had when it was neutral would have had to be lost? A) B) C)1.9 × 10^-20 D)1.4 × 10^-21

Accepted Answer

The answer of A small piece of aluminum (atomic number...

Question 14

What is the electric field strength at x = 0 m,y = 0 m produced by two electrons,one at x = 0.0001 m,y = 0 m and the other at x = -0.0001 m,y = 0 m? (The value of k is 9.0 × 10⁹ N·m²/C². ) A)0 N/C B)1.8 × 10^-19 N/C C)2.88 × 10^-19 N/C D)5.76 × 10^-19 N/C

Accepted Answer

The electric fields produced by the two electrons at the origin are equal in magnitude but opposite in direction, thus they cancel each other out, resulting in a net electric field of 0 N/C at the origin.

Question 15

In the figure Q = 5.8 nC and all other quantities are exact.What is the magnitude of the force on the charge Q? A)1.8 × 10^-3N B)1.0 × 10^-3 N C)9.0 × 10^-4 N D)1.2 × 10^-3 N

Accepted Answer

The answer of In the figure Q = 5.8 nC...

Question 16

In the figure below the charge in the middle is Q = -3.1 nC.For what charge q1 will charge q2 be in static equilibrium? 
A)12 nC
B)6.2 nC
C)3.1 nC
D)25 nC

Accepted Answer

The answer of In the figure below the charge in...

Question 17

Suppose a van de Graaff generator builds a negative static charge,and a grounded conductor is placed near enough to it so that a 7.0 μC of negative charge arcs to the conductor.Calculate the number of electrons that are transferred. A)4.38 × 10¹³ B)7.0 C)1.12 × 10^-18 D)43.8

Accepted Answer

The charge of one electron is approximately -1.6 × 10^-19 C. To find the number of electrons transferred, divide the total charge by the charge of one electron: 7.0 μC / 1.6 × 10^-19 C/electron = 4.38 × 10^13 electrons.

Question 18

A proton is located at x = 1.0 nm,y = 0.0 nm and an electron is located at x = 0.0 nm, y = 4.0 nm.Find the attractive Coulombic force between them.(The value of k is 9.0 × 10⁹ N·m²/C². ) A)1.4 × 10^-11 N B)5.3 × 10^-18 N C)5.3 × 10⁸ N D)5.9 × 10^-15 N

Accepted Answer

The attractive Coulombic force between a proton and an electron is given by:$$F = k\frac{e^2}{r^2}$$where:* k is the Coulomb constant (9.0 × 10^9 N·m^2/C^2)* e is the elementary charge (1.6 × 10^-19 C)* r is the distance between the proton and the electronIn this problem, the distance between the proton and the electron is:$$r = \sqrt{(1.0 	ext{ nm})^2 + (4.0 	ext{ nm})^2} = 4.12 	ext{ nm} = 4.12 	imes 10^{-9} 	ext{ m}$$Substituting these values into the equation for the Coulombic force, we get:$$F = (9.0 	imes 10^9 	ext{ N·m}^2/	ext{C}^2)\frac{(1.6 	imes 10^{-19} 	ext{ C})^2}{(4.12 	imes 10^{-9} 	ext{ m})^2} = 1.4 	imes 10^{-11} 	ext{ N}$$Therefore, the attractive Coulombic force between the proton and the electron is 1.4 × 10^-11 N.

Question 19

What is the magnitude of an electric field that balances the weight of a plastic sphere of mass 6.4 g that has been charged to -3.0 nC? A)2.1 × 10⁷ N/C B)2.4 × 10⁶ N/C C)4.5 × 10⁶ N/C D)6.4 × 10⁶ N/C

Accepted Answer

The electric force on the sphere is equal to the weight of the sphere, so:$$qE = mg$$where:* q is the charge on the sphere (-3.0 nC)* E is the electric field strength* m is the mass of the sphere (6.4 g)* g is the acceleration due to gravity (9.8 m/s^2)Solving for E, we get:$$E = \frac{mg}{q} = \frac{(6.4 	imes 10^{-3} 	ext{ kg})(9.8 	ext{ m/s}^2)}{-3.0 	imes 10^{-9} 	ext{ C}} = 2.1 	imes 10^7 	ext{ N/C}$$

Question 20

What is the strength of an electric field that a 0.010 C negative charge experiences 0.90 mm from a 0.20 C positive charge? (The value of K is 9.0 × 10⁹ N·m²/C². ) A)2.2 × 10¹⁵ N/C B)5.6 × 10¹⁶ N/C C)1.1 × 10¹⁵ N/C D)2.2 × 10¹⁶ N/C

Accepted Answer

The electric field strength E is calculated using the formula E = K * |q| / r^2, where q is the charge creating the field and r is the distance. Substituting the given values: E = (9.0 × 10^9 N·m^2/C^2) * (0.20 C) / (0.0009 m)^2 = 2.2 × 10^15 N/C.

Quiz 20: Electric Fields and Forces

Two electrons are passing 26.0 mm apart.What is the electric repulsive force that they exert on each other? (The value of k is 9.0 × 109 N·m2/C2. )

The charge in the bottom right corner of the figure is Q =- 45 nC.What is the magnitude of the force on Q?

A metal sphere is insulated electrically and is given a charge.If 25 electrons are added to the sphere in giving a charge,how many Coulombs are added to the sphere?

The charge at the bottom of the figure is Q = + 17 nC.What is the magnitude of the force on the charge Q?

An asteroid has acquired a net charge of 105 C from being bombarded by the solar wind over the years,and is currently in equilibrium whereby it expels electrons at the same rate as it acquires them.How many more electrons does it have than protons?

An asteroid of mass 58,000 kg carrying a negative charge of 15.0 μC is 180 m from a second asteroid of mass 52,000 kg carrying a negative charge of 11.0 μC .What is the net force the asteroids exert upon each other? (G = 6.673 × 10-11 N·m2/kg2 and k = 9.0 × 109 N·m2/C2. )

Two like charges of the same magnitude are 5.0 mm apart.If the force of repulsion they exert upon each other is 2.0 N,what is the magnitude of each charge? (The constant of proportionality for the Coulombic force is 9.0 × 109 N·m2/C2. )

A 3.0 μC positive charge is located at the origin and a 2.0 μC positive charge is located at x = 0.0 m,y = 1.0 m.Find the point between them where the electric field strength is zero.

A small glass bead has been charged to 8.0 nC? What is the strength of the electric field 2.0 cm from the center of the bead?

Two equally charged spheres of mass 1.0 g are placed 2.0 cm apart.When released,they begin to accelerate at 414 m/s2.What is the magnitude of the charge on each sphere?

The electric field 2.8 cm from a small object points toward the object with a strength of 180,000 N/C.What is the object's charge?

What is the electric field strength at x = 0 m,y = 0 m produced by two electrons,one at x = 0.0001 m,y = 0 m and the other at x = -0.0001 m,y = 0 m? (The value of k is 9.0 × 109 N·m2/C2. )

In the figure Q = 5.8 nC and all other quantities are exact.What is the magnitude of the force on the charge Q?

In the figure below the charge in the middle is Q = -3.1 nC.For what charge q1 will charge q2 be in static equilibrium?

Suppose a van de Graaff generator builds a negative static charge,and a grounded conductor is placed near enough to it so that a 7.0 μC of negative charge arcs to the conductor.Calculate the number of electrons that are transferred.

A proton is located at x = 1.0 nm,y = 0.0 nm and an electron is located at x = 0.0 nm, y = 4.0 nm.Find the attractive Coulombic force between them.(The value of k is 9.0 × 109 N·m2/C2. )

What is the magnitude of an electric field that balances the weight of a plastic sphere of mass 6.4 g that has been charged to -3.0 nC?

What is the strength of an electric field that a 0.010 C negative charge experiences 0.90 mm from a 0.20 C positive charge? (The value of K is 9.0 × 109 N·m2/C2. )

Two electrons are passing 26.0 mm apart.What is the electric repulsive force that they exert on each other? (The value of k is 9.0 × 10⁹ N·m²/C². )

An asteroid of mass 58,000 kg carrying a negative charge of 15.0 μC is 180 m from a second asteroid of mass 52,000 kg carrying a negative charge of 11.0 μC .What is the net force the asteroids exert upon each other? (G = 6.673 × 10^-11 N·m²/kg² and k = 9.0 × 10⁹ N·m²/C². )

Two like charges of the same magnitude are 5.0 mm apart.If the force of repulsion they exert upon each other is 2.0 N,what is the magnitude of each charge? (The constant of proportionality for the Coulombic force is 9.0 × 10⁹ N·m²/C². )

Two equally charged spheres of mass 1.0 g are placed 2.0 cm apart.When released,they begin to accelerate at 414 m/s².What is the magnitude of the charge on each sphere?

What is the electric field strength at x = 0 m,y = 0 m produced by two electrons,one at x = 0.0001 m,y = 0 m and the other at x = -0.0001 m,y = 0 m? (The value of k is 9.0 × 10⁹ N·m²/C². )

A proton is located at x = 1.0 nm,y = 0.0 nm and an electron is located at x = 0.0 nm, y = 4.0 nm.Find the attractive Coulombic force between them.(The value of k is 9.0 × 10⁹ N·m²/C². )

What is the strength of an electric field that a 0.010 C negative charge experiences 0.90 mm from a 0.20 C positive charge? (The value of K is 9.0 × 10⁹ N·m²/C². )