Free fall

Definition

Free fall is the motion of an object under the influence of gravitational force only, with no other forces acting on it, such as air resistance. In this state, all objects fall at the same acceleration regardless of their mass, typically at a rate of approximately 9.81 m/s² near the surface of the Earth. This uniform acceleration connects to key principles in kinematics and dynamics, particularly as it relates to rectilinear motion.

5 Must Know Facts For Your Next Test

1. In free fall, all objects experience the same acceleration due to gravity, meaning a feather and a hammer dropped from the same height will hit the ground at the same time in a vacuum.
2. Free fall can be demonstrated through experiments, such as dropping objects in a vacuum chamber to eliminate air resistance.
3. The equations of motion for an object in free fall can be derived from basic kinematics, emphasizing constant acceleration.
4. Free fall continues until the object reaches a point where it can no longer accelerate, such as when it encounters air resistance or another force.
5. Understanding free fall is crucial for analyzing various dynamics problems, including those involving falling objects and projectiles.

Review Questions

• How does free fall illustrate the concept of uniform acceleration, and what role does gravity play in this phenomenon?
  • Free fall exemplifies uniform acceleration because all objects experience the same gravitational pull when falling freely towards Earth. This consistent force results in a steady increase in velocity at approximately 9.81 m/s². Gravity is the sole force acting on a freely falling object, allowing us to observe how different masses do not affect the rate of acceleration in this context.
• Discuss how free fall differs from projectile motion and how both concepts are related through their equations of motion.
  • Free fall differs from projectile motion primarily in that free fall occurs when an object is dropped straight down under gravity alone, while projectile motion involves an initial horizontal velocity causing a curved path. Both concepts are interrelated as they can be analyzed using similar equations of motion that account for gravitational acceleration. For example, in both scenarios, the vertical component experiences the same gravitational pull, allowing for a unified approach to solving problems related to both types of motion.
• Evaluate the implications of air resistance on free fall and how this affects our understanding of real-world applications such as skydiving.
  • Air resistance significantly alters free fall by introducing a drag force that counteracts gravity, resulting in terminal velocity. This means that as a skydiver falls, they accelerate until they reach a speed where gravity and air resistance balance out, leading to a constant descent speed. Evaluating these effects not only enhances our understanding of dynamics but also impacts practical applications such as designing parachutes and safety gear for extreme sports.

Related terms

Acceleration due to gravity: The constant acceleration experienced by an object when in free fall near the Earth's surface, typically denoted as 9.81 m/s².

Projectile motion: The motion of an object that is thrown or projected into the air, which follows a curved path due to the influence of gravity and initial velocity.

Terminal velocity: The constant speed reached by an object falling through a fluid (like air) when the force of gravity is balanced by the drag force of the fluid.