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 the fundamental force responsible for the motion of celestial bodies and the behavior of objects on Earth.

5 Must Know Facts For Your Next Test

1. Gravitational force is one of the four fundamental forces in nature, along with electromagnetic, strong nuclear, and weak nuclear forces.
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 Law of Universal Gravitation.
3. Gravitational force is responsible for the motion of planets, stars, and galaxies, as well as the behavior of objects on Earth, such as the acceleration due to gravity and the weight of objects.
4. The gravitational force acting on an object near the Earth's surface is the force that gives the object its weight, which is equal to the object's mass multiplied by the gravitational acceleration.
5. Gravitational force is a conservative force, meaning that the work done by the force is independent of the path taken, and the total energy of a system is conserved when only gravitational forces are present.

Review Questions

• Explain how the gravitational force between two objects is related to their masses and the distance between them.
  • According to Newton's Law of Universal 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, and as the distance between them increases, the gravitational force decreases rapidly. This relationship is the foundation for understanding the motion of celestial bodies and the behavior of objects on Earth under the influence of gravity.
• Describe how the gravitational force is related to the concept of weight and the acceleration due to gravity.
  • The gravitational force acting on an object near the Earth's surface is the force that gives the object its weight, which is equal to the object's mass multiplied by the gravitational acceleration, typically denoted as 'g' and having a value of approximately 9.8 m/s^2 near the Earth's surface. This acceleration due to gravity is a direct result of the gravitational force acting on the object, and it is this acceleration that causes objects to fall towards the Earth's surface at a constant rate, regardless of their mass.
• Explain the significance of gravitational force being a conservative force and how this relates to the conservation of energy in a system.
  • Gravitational force is a conservative force, meaning that the work done by the force is independent of the path taken, and the total energy of a system is conserved when only gravitational forces are present. This has important implications for the study of mechanics and the analysis of systems under the influence of gravity. For example, in the case of a pendulum, the total mechanical energy of the system (the sum of the potential energy due to the gravitational force and the kinetic energy of the pendulum's motion) remains constant, and the energy is simply converted between these two forms as the pendulum swings back and forth.

Related terms

Newton's Law of Universal Gravitation: The law that states that any two objects with mass exert a gravitational force on each other that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

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

Weight: The force exerted on an object by gravity, which is equal to the object's mass multiplied by the gravitational acceleration.