Kepler law of motion

What shape do planets follow in their orbits around the sun according to Kepler's first law?

• Circular

• Elliptical

• Square

• Triangular

Kepler's second law states that a radius vector joining a planet to the sun sweeps out equal areas in equal lengths of time. What does this imply about a planet's speed?

• It moves at a constant speed throughout its orbit.
  

• It moves faster when it is closer to the sun and slower when it is farther away.
  

• Its speed is unrelated to its distance from the sun.
  

• It moves faster when it is farther from the sun.

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According to Kepler's third law, what is the relationship between the squares of a planet's orbital periods and the cubes of their mean distances from the sun?

• They are inversely proportional.
  

• They are unrelated.
  

• They are directly proportional.
  

• They are equal.

What does Kepler's third law help compare among different planets?

• Their colours
  

• Their speeds
  

• Their orbital periods and mean distances from the sun
  

• Their sizes