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# What does Kepler's second law imply?

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Kepler's second law implies that the closer a planet is to its star, the faster the planet travels. This law is related to conservation of angular momentum. The law is important because the planets' orbits around stars are not circular, so planets are closer to their stars at certain points.

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Kepler's second law assumes that if a line is drawn between a star and its planet, for any set time period, that line sweeps out the same area each period, no matter where in orbit the planet is at the time.

For example, if the time period is 10 days, the line between the planet and the star sweeps out equal areas every 10 days. This is possible because when the planet is closer to its star, it moves faster, and when it is further away from its star, it moves slower. At aphelion, the point in a planet's orbit furthest away from the star, the planet moves the slowest. At perihelion, the planet is closest to its star and moves the fastest. This is because of the planet's conservation of angular momentum.

Angular momentum is directly proportional to an object's moment of inertia and angular velocity. When a planet's distance from its star increases, its moment of inertia increases. For its angular momentum to remain the same, the planet's angular velocity has to decrease.

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## Related Questions

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The concept of air resistance is related to Newton's second law of motion, which describes acceleration and force. Air resistance is a significant factor in how fast an object falls, according to this law.

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Newton’s second law states that the force acting on an object is directly related to the acceleration. The law is formulated as F = m x a, where F = force, a = acceleration and m = mass of the object in motion. In terms of Atwood’s machine, a force equal to the difference in the suspended weights accelerates the total mass, m1+ m2.

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An example of Newton's second law of motion would be if someone's car ran out of gas and they tried to push it and, because the car is much heavier, it would require more force to push than if it was a lighter object, like a bicycle. This example relates to Newton's second law of motion because this law stipulates that the heavier an object is, the more force will be required to move the object and give it acceleration.