Question

Suppose that two objects attract each other with a gravitational force of 18 units. If the mass of one of the objects was tripled, and if the distance between the objects tripled, then what would be the new gravitational force of attraction between the two objects?

Answer 1

6 units

Step-by-step explanation:

You want the gravitational force between two objects after both the mass of one object and the distance between them triples, if it is initially 18 units.

Force

Let F represent the initial force between the objects. Newton's law of gravitational attraction tells us ...

F = GmM/r²

When one mass is tripled, and the distance between the objects is tripled, the new force is ...

F' = G(3m)M/(3r)² = 3/9(GmM/r²) = F/3

Given the initial force is 18 units, the new force of attraction is ...

F' = (18 units)/3 = 6 units

The new gravitational force of attraction between the objects is 6 units.