Newton's law of gravity and Coulomb's law are both inverse-
square laws. Consequently, there should be a "Gauss's law for
gravity."
a. The electric field was defined as
to find the electric field of a point charge. Using analogous
reasoning, what is the gravitational field
Write your answer using the unit vector
signs; the gravitational force between two "like masses" is
attractive, not repulsive.
b. What is Gauss's law for gravity, the gravitational equivalent
of Equation 24.18? Use
gravitational field, and Min for the enclosed mass.
c. A spherical planet is discovered with mass M, radius R, and
a mass density that varies with radius as
where
of M and R.
Hint: Divide the planet into infinitesimal shells of thickness dr,
then sum (i.e., integrate) their masses.
d. Find an expression for the gravitational field strength inside
the planet at distance r < R.
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Chapter 24 Solutions
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics, Books a la Carte Edition; Student Workbook for Physics for Scientists ... eText -- ValuePack Access Card (4th Edition)
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