What does gravitational field strength define?

Gravitational field strength is defined as the force experienced by a unit mass in a gravitational field. It quantifies how much gravitational force is acting on an object with a mass of 1 kilogram. This means that the gravitational field strength provides a direct measure of the intensity of the gravitational force exerted by a planet at a given location.

For example, on Earth, the gravitational field strength is approximately 9.81 N/kg. This indicates that any 1 kg mass placed in this field would experience a force of about 9.81 Newtons directed towards the center of the Earth.

In contrast, while the weight of an object relates to both the mass of the object and the gravitational field strength, it does not solely define gravitational field strength itself. The acceleration of free-falling objects does relate to gravitational field strength, as the acceleration due to gravity is a consequence of this strength, but it is an effect rather than a definition. The distance to the center of the planet is a measure that can influence gravitational field strength, but it does not define what gravitational field strength actually is.

Thus, understanding gravitational field strength in terms of the force on a kg mass effectively encapsulates its definition within the context of gravitational systems.