Question

if the original force between two objects is 0.90 N, and the distance is tripled, what is the new gravitational force between the objects.

Answer 1

New force is 0.10 N

Explanation:

We have equation for gravitational force

          $F=\frac{GMm}{r^2}$

  where G is gravitational constant, M is mass of object 1 , m is mass of object 2 and r is the separation.

Here only r is changing, it changes to triple the earlier value.

                  r ⇒ 3r

    $\frac{F_1}{F_2}=\frac{\frac{GMm}{r^2}}{\frac{GMm}{(3r)^2}}\\\\\frac{F_1}{F_2}=9\\\\F_2=\frac{F_1}{9}$

  Given that F₁ = 0.90 N

Substituting

    $F_2=\frac{0.90}{9}=0.10N$

New force is 0.10 N