Pluto and Charon

i / Example 3. Computerenhanced images of Pluto and Charon, taken by the Hubble Space Telescope.

Pluto's moon Charon is unusually large considering Pluto's size, giving them the character of a double planet. Their masses are 1.25×10²² and 1.9x19²¹ kg, and their average distance from one another is 1.96×10⁴ km. What is the gravitational force between them?

If we want to use the value of G expressed in SI (meter-kilogramsecond) units, we first have to convert the distance to 1.96 × 10⁷ m.

The force is