21. The gravitational force between two objects is directly proportional to the:
a) Mass of one object
b) Mass of the other object
c) Distance between the objects
d) Both the masses and the distance between the objects
22. Which of the following is not a unit of gravitational force?
a) Newton
b) Dyne
c) Pound
d) Kilogram-meter per second squared
23. The value of gravitational constant G is approximately:
a) 6.67 × 10⁻¹¹ N·m²/kg²
b) 9.8 m/s²
c) 3 × 10⁸ m/s
d) 3 × 10⁸ m/s²
24. The gravitational force between two objects is stronger when their distance apart is:
a) Small
b) Large
c) Equal to zero
d) Unrelated to their distance apart
25. The gravitational force between two objects is inversely proportional to the:
a) Cube of their masses
b) Cube of the distance between them
c) Square of their masses
d) Square of the distance between them
