Acceleration due to gravity

Definition

Acceleration due to gravity is the acceleration experienced by an object when it is in free fall towards the Earth, primarily caused by the gravitational pull of the planet. This acceleration is approximately $$9.81 \, \text{m/s}^2$$ at Earth's surface and is a key factor in understanding motion, particularly for objects falling under the influence of gravity without any air resistance.

5 Must Know Facts For Your Next Test

1. The value of acceleration due to gravity can slightly vary depending on location due to factors like altitude and Earth's rotation.
2. In a vacuum, all objects fall with the same acceleration due to gravity regardless of their mass.
3. When graphing free fall motion, a velocity-time graph will show a straight line with a slope equal to the acceleration due to gravity.
4. The distance fallen by an object in free fall increases with the square of the time elapsed, as shown in kinematic equations.
5. The concept of terminal velocity occurs when an object's weight is balanced by air resistance, resulting in no further acceleration despite gravity acting on it.

Review Questions

• How does acceleration due to gravity affect the motion of falling objects?
  • Acceleration due to gravity causes falling objects to accelerate towards the Earth at a rate of approximately $$9.81 \, \text{m/s}^2$$. This means that as time progresses, the velocity of a freely falling object increases linearly while its distance traveled increases quadratically. This relationship is crucial in understanding how quickly an object will fall and how far it will go during its descent.
• Compare and contrast free fall and uniform motion in terms of acceleration due to gravity.
  • Free fall involves an object accelerating towards the Earth solely under the influence of gravity, leading to an increase in velocity over time. In contrast, uniform motion describes an object moving at a constant velocity with no net acceleration. The key difference lies in how acceleration due to gravity impacts free-falling objects by increasing their speed, while uniformly moving objects maintain a constant speed without changing direction.
• Evaluate how the concept of acceleration due to gravity influences practical applications like skydiving and projectile motion.
  • In skydiving, understanding acceleration due to gravity is essential for predicting free fall behavior and calculating terminal velocity. Divers initially accelerate downward until they reach terminal velocity when air resistance equals gravitational force. In projectile motion, this concept helps determine trajectories, as vertical motion is influenced by gravity while horizontal motion remains unaffected. Combining these principles allows for accurate predictions of landing points and safety measures in various activities.

Related terms

Free Fall: The motion of an object where gravity is the only force acting upon it, resulting in constant acceleration.

Gravitational Force: The attractive force between two masses, such as the Earth and an object, which determines the object's weight and its acceleration due to gravity.

Kinematic Equations: A set of equations that relate an object's displacement, velocity, acceleration, and time, commonly used to analyze motion including free fall.