An Apollo command module orbited the Moon about 100 km above the surface. What was its orbital velocity? What was its orbital period? (Hint: Use the formula for circular velocity, Eq. 5-1a.) (Note: Relevant information can be found in Celestial Profile: The Moon.)
The orbital period of the Apollo command module.
Answer to Problem 8P
The orbital period of the Apollo command module is
Explanation of Solution
The expression for the orbital period of the Apollo command module is given by,
Here,
The expression for the orbital velocity of the object is,
Here,
The expression for the gravitational acceleration at an altitude from the surface of a planet is,
Here,
Substitute
Conclusion:
Substitute
Substitute
Solve further as,
Therefore, the orbital period of the Apollo command module is
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Chapter 20 Solutions
EBK FOUNDATIONS OF ASTRONOMY
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