Question

A spacecraft travels directly from Earth to the Moon. Where is the vector sum of the gravitational forces exerted on the spacecraft by Earth and by the Moon zero?

Answer 1

Gravitational force, F is directly proportional to the mass of the object.

The mass of the satellite is the same for both earth and the moon.

So, Gravitational force of earth > gravitational force of the moon

Also, the distance is inversely proportional to the gravitational force.

Thus, the vector sum of gravitational force due to earth and due to the moon on the satellite will be zero, when the satellite is more than halfway to the moon.