Concept explainers
(a)
The surface charge density of the ground.
(a)
Answer to Problem 54AP
The surface charge density of the ground is
Explanation of Solution
Write the expression for the electric field due to charged earth immediately above its surface.
Here,
Write the expression for the surface charge density.
Here,
Substitute
Conclusion:
Substitute
Since the electric field is directed downward. Hence, the surface charge density will be negative.
Therefore, the surface charge density of the ground is
(b)
The charge of the whole surface of the earth.
(b)
Answer to Problem 54AP
The charge of the whole surface of the earth is
Explanation of Solution
Conclusion:
Substitute
Therefore, the charge of the whole surface of the earth is
(c)
The earth’s electric potential.
(c)
Answer to Problem 54AP
The earth’s electric potential is
Explanation of Solution
Write the expression for the electric potential.
Here,
Conclusion:
Substitute
Therefore, The earth’s electric potential is
(d)
The difference in potential between the head and foot of a person.
(d)
Answer to Problem 54AP
The difference in potential between the head and foot of a person is
Explanation of Solution
Write the relationship between the electric potential and the electric field.
Here,
Conclusion:
Substitute
Therefore, the difference in potential between the head and foot of a person is
(e)
The force that the earth would exert on the moon.
(e)
Answer to Problem 54AP
The force that the earth would exert on the moon is
Explanation of Solution
Write the expression for the magnitude of electrostatic force exerted by the earth on the moon.
Here,
Conclusion:
Substitute
Therefore, the force that the earth would exert on the moon is
(f)
The comparison between the gravitational force and the electrostatic force exerted by the earth on the moon.
(f)
Answer to Problem 54AP
The gravitational force is
Explanation of Solution
Write the expression for the gravitational force between the earth and moon.
Here,
Write the expression to calculate the ratio of gravitational force and the electrostatic force between the earth and the moon.
Conclusion:
Substitute
Substitute
Therefore, the gravitational force is
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Chapter 25 Solutions
Physics for Scientists and Engineers With Modern Physics
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- The three charged particles in Figure P20.11 are at the vertices of an isosceles triangle (where d = 2.00 cm). Taking q = 7.00 C, calculate the electric potential at point A, the midpoint of the base. Figure P20.11arrow_forwardA uniformly charged insulating rod of length 14.0 cm is bent into the shape of a semicircle as shown in Figure P20.29. The rod has a total charge of 7.50 C. Find the electric potential at O, the center of the semicircle. Figure P20.29arrow_forwardThe three charged particles in Figure P25.22 are at the vertices of an isosceles triangle (where d = 2.00 cm). Taking q = 7.00 C, calculate the electric potential at point A, the midpoint of the base.arrow_forward
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