Gravitational Field

Gravitational field strength describes how strongly gravity acts at a point in space. We define it as:

$$g = \dfrac{F_g}{m}$$

Here $F_g$ is the gravitational force on an object of mass $m$. The units are newtons per kilogram (N/kg). This tells us the force per unit mass at that location.

The field model helps us understand noncontact forces like gravity. Instead of two masses attracting across empty space, we think of it differently. Each mass creates a gravitational field around it. When another mass enters this field, it experiences a force.

The field exists even when no object is there to feel it. The field is a property of space itself, created by the source mass.

This separates the interaction into two parts. First, the source mass creates a field. Second, a test mass responds to that field.

The field strength $g$ at any point depends only on the source mass and location. It does not depend on the mass experiencing the force. A heavier object feels a larger force ($F_g = m \cdot g$), but $g$ stays the same.

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