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Question
State Kepler's laws of planetary motion.
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Solution
Kepler’s first law (Law of orbit):
Every planet revolves around the sun in an elliptical orbit with the sun situated at one of the focii of the ellipse
Kepler’s second law (Law of equal areas):
The radius vector drawn from the sun to any planet sweeps out equal areas in equal intervals of time, i.e., areal velocity of the radius vector is constant.
Kepler’s third law (Law of periods):
The square of the period of revolution of the planet round the sun is directly proportional to the cube of the semi-major axis of the elliptical orbit
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