1. Who discovered the concept of gravity? a) Albert Einstein b) Isaac Newton c) Galileo Galilei d) Johannes Kepler Answer: b) Isaac Newton

2. What is the acceleration due to gravity at Earth's surface? a) 9.81 m/s^2 b) 1.62 m/s^2 c) 3.71 m/s^2 d) 24.79 m/s^2 Answer: a) 9.81 m/s^2

3. Which of the following factors affects the strength of gravitational force between two objects? a) Distance between objects b) Mass of objects c) Both a) and b) d) None of the above Answer: c) Both a) and b)

4. Which planet has the strongest gravitational pull? a) Earth b) Jupiter c) Saturn d) Neptune Answer: b) Jupiter

5. What is the formula to calculate the force of gravity between two objects? a) F = m/g b) F = G(m1m2)/d^2 c) F = ma d) F = mv Answer: b) F = G(m1m2)/d^2

6. 1. Who formulated the law of gravitation? A) Isaac Newton B) Albert Einstein C) Johannes Kepler D) Galileo Galilei

   Answer: A) Isaac Newton

   2. Newton's law of gravitation states that: A) The force of gravity between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them B) The force of gravity between two objects is directly proportional to the square of the distance between them and inversely proportional to the product of their masses C) The force of gravity between two objects is directly proportional to the distance between them and inversely proportional to the product of their masses D) The force of gravity between two objects is directly proportional to the product of their masses and the distance between them

   Answer: A) The force of gravity between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them

   3. The proportionality constant in Newton's law of gravitation is known as: A) Coulomb's constant B) Planck's constant C) Boltzmann's constant D) Newton's constant

   Answer: D) Newton's constant

   4. What is the direction of the force of gravity between two objects? A) Opposite to the direction of motion of the objects B) Along the direction of motion of the objects C) Perpendicular to the direction of motion of the objects D) None of the above

   Answer: D) None of the above. The force of gravity is always in the direction of the line joining the centers of the two objects.

   5. If the distance between two objects is doubled, what happens to the force of gravity between them? A) It is halved B) It is quadrupled C) It is doubled D) It is reduced to one-fourth

   Answer: A) It is halved. The force of gravity is inversely proportional to the square of the distance between the objects.