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A comet moves in an elliptical orbit around the sun. The closest distance of the comet from the sun (perihelion) is 72 * 10⁶ m and the farthest distance (aphelion) is 144 * 10⁶ m. The ratio of the comet's maximum speed to its minimum speed in the orbit is (ignore all bodies except the sun and the comet):

1. 2
2. sqrt(2)
3. 3
4. 4

Correct answer: 2

Solution

By conservation of angular momentum, v_max / v_min = r_max / r_min = 144 / 72 = 2.

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