Exam-style question
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A satellite is in a circular orbit around a planet. If the orbital radius is doubled, how does the orbital speed change? Explain your reasoning.
Model answer
What a good answer should say
- The orbital speed decreases by a factor of √2.
- This is because the orbital speed (v) is related to the radius (r) by the formula v = √(GM/r), where G is the gravitational constant and M is the mass of the planet.
- Doubling the radius increases the denominator, thus reducing the speed.
Explanation
Why this works
This question tests the understanding of the relationship between orbital radius and speed in circular orbits. The answer is strong because it applies the relevant formula and explains how changes in radius affect speed.
Common mistake
No common mistake is linked to this question yet.