Acceleration Due to Gravity

Definition

Acceleration due to gravity, often denoted as 'g', is the acceleration experienced by an object due to the Earth's gravitational pull. This constant acceleration acts on all objects near the Earth's surface, causing them to experience a downward force and a change in velocity over time.

5 Must Know Facts For Your Next Test

1. The value of acceleration due to gravity on Earth's surface is approximately 9.8 m/s^2, directed downward.
2. Acceleration due to gravity is independent of an object's mass, as described by Galileo's experiments and Newton's Second Law of Motion.
3. Gravitational potential energy is directly proportional to the mass of an object and its height above the Earth's surface, as given by the formula $U = mg h$.
4. Archimedes' Principle states that the buoyant force on an object submerged in a fluid is equal to the weight of the fluid displaced, which is affected by acceleration due to gravity.
5. Bernoulli's Equation relates the pressure, velocity, and elevation of a fluid, with the acceleration due to gravity being a key component in the equation.

Review Questions

• Explain how acceleration due to gravity affects the motion of objects in two-dimensional kinematics.
  • In two-dimensional kinematics, acceleration due to gravity plays a crucial role in the motion of objects, particularly in the vertical component of their trajectory. Gravity causes a constant downward acceleration on all objects near the Earth's surface, which influences their vertical displacement, velocity, and acceleration over time. This effect is seen in the motion of projectiles, where the vertical motion is governed by the acceleration due to gravity, while the horizontal motion is determined by the initial velocity and angle of launch.
• Describe the relationship between acceleration due to gravity, Newton's Universal Law of Gravitation, and gravitational potential energy.
  • Acceleration due to gravity is directly related to Newton's Universal Law of Gravitation, which states that any two objects with mass exert a gravitational force on each other. This force is proportional to the masses of the objects and inversely proportional to the square of the distance between them. The acceleration due to gravity experienced by an object near the Earth's surface is a result of this gravitational force. Furthermore, the gravitational potential energy of an object is defined as the work done by the gravitational force in lifting the object to a certain height, and it is directly proportional to the mass of the object and its height above the Earth's surface, as given by the formula $U = mg h$.
• Analyze how acceleration due to gravity affects the buoyant force described by Archimedes' Principle and the pressure-velocity relationship in Bernoulli's Equation.
  • Acceleration due to gravity is a critical factor in both Archimedes' Principle and Bernoulli's Equation. Archimedes' Principle states that the buoyant force on an object submerged in a fluid is equal to the weight of the fluid displaced, which is directly influenced by the acceleration due to gravity. The greater the acceleration due to gravity, the greater the weight of the displaced fluid and, consequently, the greater the buoyant force acting on the object. Similarly, in Bernoulli's Equation, which relates the pressure, velocity, and elevation of a fluid, the acceleration due to gravity is a key component in the equation, as it affects the potential energy of the fluid. Changes in the acceleration due to gravity would directly impact the pressure-velocity relationship described by Bernoulli's Equation.

Related terms

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

Free Fall: The motion of an object under the sole influence of gravity, with no other external forces acting upon it.

Projectile Motion: The motion of an object that is launched into the air, subject to the effects of gravity and air resistance.