Gravitational Field

Definition

The gravitational field is a region of space surrounding a massive object, such as a planet or star, where the force of gravity acts upon other objects. It describes the strength and direction of the gravitational force at every point in that region of space.

5 Must Know Facts For Your Next Test

1. The gravitational field is an inverse-square field, meaning the strength of the gravitational force decreases with the square of the distance from the massive object.
2. The direction of the gravitational field at a point is always towards the center of the massive object creating the field.
3. The strength of the gravitational field is measured in newtons per kilogram (N/kg) and represents the gravitational force per unit mass.
4. The gravitational field is responsible for the acceleration of objects towards the massive object, as described by Newton's Second Law of Motion.
5. Variations in the gravitational field can be used to detect the presence of underground masses, such as oil or mineral deposits, through the use of gravimetry.

Review Questions

• Explain how the concept of the gravitational field is related to Newton's Universal Law of Gravitation.
  • The gravitational field is a direct consequence of Newton's Universal Law of Gravitation, which states that any two objects with mass exert an attractive force on each other that is proportional to their masses and inversely proportional to the square of the distance between them. The gravitational field describes the strength and direction of this gravitational force at every point in space surrounding a massive object, allowing us to predict the motion of other objects within that field.
• Describe how the gravitational field is related to the concept of gravitational potential energy.
  • The gravitational field is directly linked to the concept of gravitational potential energy. Gravitational potential energy is the potential energy an object possesses due to its position within a gravitational field. The gravitational potential at a point in the field is equal to the work done per unit mass in moving an object from infinity to that point. The gradient of the gravitational potential, or the rate of change of the potential with distance, is equal to the strength of the gravitational field at that point.
• Analyze how variations in the gravitational field can be used to detect the presence of underground masses.
  • Subtle variations in the strength of the gravitational field can be used to detect the presence of underground masses, such as oil or mineral deposits, through the technique of gravimetry. Denser underground structures will create a slightly stronger local gravitational field, which can be measured using highly sensitive gravimeters. By mapping these small changes in the gravitational field, geologists can infer the location and approximate size of subsurface features that have a different density than the surrounding rock. This information is valuable for exploration and resource extraction purposes.

Related terms

Gravitational Force:

The attractive force that exists between any two objects with mass, as described by Newton's Universal Law of Gravitation.

Gravitational Acceleration: The acceleration experienced by an object due to the gravitational force acting upon it, typically denoted as 'g'.

Gravitational Potential: The potential energy per unit mass of an object within a gravitational field, which represents the work done in moving an object from infinity to that point in the field.