Gravitational Force

Definition

Gravitational force is the attractive force that exists between any two objects with mass. It is the force that causes objects to be pulled towards each other and is responsible for the motion of celestial bodies as well as the acceleration of objects near the Earth's surface.

5 Must Know Facts For Your Next Test

1. Gravitational force is one of the four fundamental forces in nature, along with the strong nuclear force, the weak nuclear force, and electromagnetism.
2. The strength of the gravitational force between two objects is directly proportional to their masses and inversely proportional to the square of the distance between them, as described by Newton's Universal Law of Gravitation.
3. Gravitational force is responsible for the motion of planets and other celestial bodies in the solar system, as well as the acceleration of objects near the Earth's surface.
4. The acceleration due to gravity, 'g', is a measure of the strength of the Earth's gravitational field and is used to calculate the force exerted on an object by the Earth's gravity.
5. Gravitational force is a conservative force, meaning that the work done by the force is independent of the path taken between two points.

Review Questions

• Explain how the gravitational force between two objects is affected by changes in their masses and the distance between them.
  • According to Newton's Universal Law of Gravitation, the gravitational force between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. This means that as the masses of the objects increase, the gravitational force between them increases proportionally. Conversely, as the distance between the objects increases, the gravitational force decreases dramatically, following an inverse square relationship. Therefore, the gravitational force between two objects is highly sensitive to changes in both their masses and the distance separating them.
• Describe the role of gravitational force in the motion of celestial bodies and the acceleration of objects near the Earth's surface.
  • Gravitational force is the primary force responsible for the motion of planets, moons, and other celestial bodies in the solar system. The gravitational attraction between these objects and the Sun causes them to orbit around the Sun in elliptical paths. Similarly, the Earth's gravitational force is responsible for the acceleration of objects near its surface, causing them to fall towards the Earth at a rate of approximately 9.8 m/s^2, known as the acceleration due to gravity. This acceleration due to gravity is what gives objects their weight and is a crucial factor in the study of falling objects and the development of the force concept.
• Analyze how the conservative nature of gravitational force relates to the concept of potential energy and the work done by the force.
  • The fact that gravitational force is a conservative force means that the work done by the force is independent of the path taken between two points. This allows for the concept of gravitational potential energy, where an object's potential energy is determined by its position relative to the source of the gravitational field, such as the Earth. As an object moves within the gravitational field, the change in its potential energy is equal to the work done by the gravitational force, regardless of the path taken. This relationship between gravitational force, potential energy, and work is a fundamental aspect of the study of mechanics and the development of the force concept.

Related terms

Gravity: The force of attraction between objects with mass, which causes them to accelerate towards each other.

Newton's Law of Universal Gravitation: The law that states that every particle in the universe attracts every other particle with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

Acceleration Due to Gravity: The acceleration experienced by an object near the Earth's surface due to the Earth's gravitational pull, typically denoted as 'g' and having a value of approximately 9.8 m/s^2.