The gravitational force between two objects in space is 800 million
newtons. If the distance between them is doubled, what size will the
gravitational force be (in millions of newtons)?
The Moon is smaller and has less mass than the Earth, so its gravitational field strength is only about one-sixth of the Earth's. So, for example, a 120 kg astronaut weighs 1200 N on Earth but only 200 N on the Moon.
