Question

Knowing the constant g what will the gravitational force between two masses be if the gravitational force between them is 36n and the distance is tripled? answer

Answer 1

The gravitational force between two masses is given by:

`F=G (m_1 m_2)/(r^2)`
where
G is the gravitational constant
m1 and m2 are the two masses
r is the separation between the two masses

We see that the force is proportional to the inverse of the square of the distance:
`F \sim (1)/(r^2)`
therefore, if the distance is tripled:
r'=3r
The force decreases by a factor 1/9:

`F \sim (1)/((3r)^2)= (1)/(9) (1)/(r^2)`

Since the original force was 36 N, the new force will be

`F' = (1)/(9) (36 N)= 4 N`