Gravitational field

Definition

A gravitational field is a region of space surrounding a mass where another mass experiences a force due to gravity. It is represented by the gravitational field strength, denoted as $g$.

5 Must Know Facts For Your Next Test

1. The gravitational field strength near Earth's surface is approximately $9.8 \text{ m/s}^2$.
2. Gravitational field lines point towards the center of the Earth.
3. The formula for gravitational field strength is $g = \frac{GM}{r^2}$, where $G$ is the gravitational constant, $M$ is the mass creating the field, and $r$ is the distance from the center of that mass.
4. Gravitational fields are vector fields; they have both magnitude and direction.
5. In uniform gravitational fields near Earth's surface, the force experienced by an object is given by $F = mg$, where $m$ is the object's mass.

Review Questions

• What is the approximate value of gravitational field strength near Earth's surface?
• How do you calculate the gravitational field strength using a planet's mass and radius?
• Why are gravitational fields considered vector fields?

Related terms

Gravitational Constant (G): A universal constant ($6.67430 \times 10^{-11} \text{ m}^3\text{/kg}\text{s}^2$) used in calculating gravitational forces between two masses.

Weight:

The force exerted on an object due to gravity, calculated as $mg$, where $m$ is mass and $g$ is gravitational field strength.

Newton's Law of Universal Gravitation:

$F = \frac{Gm_1m_2}{r^2}$ describes how every mass attracts every other mass with a force proportional to their masses and inversely proportional to the square of their separation distance.