Physics – Gravity

1. According to Kepler’s Third Law, what is the planet’s period of revolution squared directly proportional to?

  1. The cube root of the planet’s semi-major axis of its elliptical orbit
  2. The cube of the planet’s semi-major axis of its elliptical orbit
  3. The planet’s semi-major axis of its elliptical orbit
  4. The square of the planet’s semi-major axis of its elliptical orbit
Show Answer

Answer: Option B. The cube of the planet’s semi-major axis of its elliptical orbit

2. Which of the following is true of the universal gravitational constant if the centers of mass of two objects are each a unit distance apart?

  1. It equals the force of attraction between them
  2. It is equal to half of the force of attraction between them
  3. It is equal to 100 times the force of attraction between them
  4. It is equal to 3.5 times the force of attraction between them
Show Answer

Answer: Option A. It equals the force of attraction between them

3. What is the dimensional formula of the Universal Gravitational Constant?

  1. ML^{2}T^{-1}
  2. MLT^{-2}
  3. ML^{-1}T^{-2}
  4. M^{-1}L^{3}T^{-2}
Show Answer

Answer: Option D. M^{-1}L^{3}T^{-2}

4. What is another name for Kepler’s Second Law?

  1. The Law of Equal Orbits
  2. The Law of Universal Gravitation
  3. The Law of Equal Areas
  4. The Law of Inertia
Show Answer

Answer: Option C. The Law of Equal Areas

5. Which law describes that the orbits of planets are ellipses with the Sun at one of the foci?

  1. Newton’s Law of Gravitation
  2. Kepler’s First Law
  3. Kepler’s Third Law
  4. Galileo’s Law of Planetary Motion
Show Answer

Answer: Option B. Kepler’s First Law