Gravity

Definition

Gravity is a fundamental force of nature that attracts objects with mass towards each other. It is the force that keeps planets in orbit around the sun, causes objects to fall to the ground, and governs the motion of celestial bodies in the universe.

5 Must Know Facts For Your Next Test

1. Gravity is the force that causes objects to accelerate towards each other, as described by Newton's law of universal gravitation.
2. The acceleration due to gravity, 'g', is approximately 9.8 m/s^2 near the Earth's surface, and this value is used in many physics calculations.
3. Gravitational potential energy is the energy an object possesses due to its position in a gravitational field, and it is converted to kinetic energy as the object falls.
4. Centripetal force, which is the force that causes an object to move in a circular path, is often provided by the force of gravity in many physical systems.
5. Conditions for static equilibrium, where the net force and net torque on an object are zero, often involve the consideration of gravitational forces acting on the object.

Review Questions

• Explain how the concept of gravity is used in solving problems in physics.
  • Gravity is a fundamental concept in physics that is used to solve a wide range of problems. When solving problems in physics, the force of gravity must be considered, as it affects the motion and behavior of objects. For example, when analyzing the motion of a falling object, the acceleration due to gravity, 'g', is a key factor in determining the object's trajectory and the time it takes to reach the ground. Similarly, in problems involving circular motion, the gravitational force provides the necessary centripetal force to keep the object moving in a circular path. Additionally, the concept of gravitational potential energy is crucial in solving problems related to energy and work.
• Describe how the force of gravity is incorporated into Newton's second law of motion.
  • Newton's second law of motion states that the net force acting on an object is equal to the object's mass multiplied by its acceleration. The force of gravity is a key component of this law, as it is one of the forces that can act on an object and contribute to its acceleration. When an object is subjected to the force of gravity, such as an object falling near the Earth's surface, the gravitational force is included in the net force calculation, and the object's acceleration is determined by the magnitude of this force and the object's mass. Understanding the role of gravity in Newton's second law is essential for accurately predicting and analyzing the motion of objects under the influence of gravitational forces.
• Evaluate the importance of the concept of gravity in understanding centripetal force and static equilibrium.
  • The concept of gravity is crucial in understanding both centripetal force and static equilibrium. In the case of centripetal force, gravity is often the force that provides the necessary centripetal acceleration to keep an object moving in a circular path, such as the motion of planets around the sun or the motion of a satellite orbiting the Earth. Without the gravitational force, the object would not be able to maintain its circular trajectory. Similarly, in the context of static equilibrium, the force of gravity acting on an object must be considered when determining the net force and net torque acting on the object. For an object to be in a state of static equilibrium, the gravitational force, along with any other forces, must be balanced, resulting in a net force and net torque of zero. Understanding the role of gravity in these fundamental physics concepts is essential for solving a wide range of problems.

Related terms

Gravitational Force:

The attractive force between two objects with mass, as described by Newton's law of universal gravitation.

Acceleration Due to Gravity:

The constant acceleration experienced by an object near the Earth's surface due to the Earth's gravitational pull, denoted as 'g'.

Gravitational Potential Energy: The potential energy an object possesses due to its position in a gravitational field, which is directly proportional to its mass and height above the reference point.