Which of the following statements about the movement of planets is true? A. A planet's orbit is elliptical with the Sun at one of two focal points. B. The orbit of a planet is circular with the sun in the center. C. The orbit of a planet is elliptical with another planet in one of the two center-points. D. The orbit of a planet is circular with another planet in the center.
A
Correct Option: A. A planet's orbit is elliptical with the Sun at one of two focal points.
Explanation: This statement is a direct definition of Kepler's First Law of Planetary Motion. Johannes Kepler discovered that planets do not travel in perfect circles. Instead, they follow an ellipse (an oval shape). An ellipse has two geometric focal points, and the Sun sits at one of these points, providing the gravitational pull that keeps the planet in orbit.
Why others are incorrect: Options B and D are incorrect because planetary orbits are not perfect circles. Option C is incorrect because the Sun is the object occupying the focal point, not another planet.
Important Questions from Gravity
Who among the following was the first to conclude that in vacuum all objects fall with the same acceleration g and reach the ground at the same time?
Who among the following is credited with postulating three laws of planetary motion?
When did Henry Cavendish report the measurement of the gravitational constant with the mass and density of the Earth?
Which of the following law states that, "The force between two objects is directly proportional to the product of their masses?"
If the mass of a person is 60 kg on the surface of earth then the same person’s mass on the surface of the moon will be:
