Answer:
d. Two soccer balls that are touching each other
Explanation:
Let be the mass of a tennis ball, is the mass of a soccer ball.
As the mass of a soccer ball is more than the mass of a tennis ball, so
Let be the distance between the centers of both the balls near each other and be the distance between the centers of both the balls touching each other.
So,
The gravitational force, F, between the two objects having masses M and m and separated by distance d is
Where G is the universal gravitational constant.
As, the gravitational force is directly proportional to the product of both the masses and inversely proportional to the square of the distance between them, so selecting the larger mass (, soccer ball) separated by a lesser distance (, touching) to get more gravitational force.
Therefore, there will be a larger gravitational force between them when two soccer balls touching each other.
Hence, option (d) is correct.