🍏principles of physics i review

key term - Free Fall

Definition

Free fall refers to the motion of an object under the influence of gravitational force only, without any other forces acting on it, like air resistance. During free fall, objects accelerate towards the Earth at a constant rate due to gravity, which connects to how motion is described and analyzed, as well as the energy transformations involved in such movements.

5 Must Know Facts For Your Next Test

  1. In free fall, all objects, regardless of mass, accelerate at the same rate when only gravity is acting on them, demonstrating that gravity affects all masses equally.
  2. The time it takes for an object to fall from a certain height can be calculated using the equation $$d = \frac{1}{2} g t^2$$, where $$d$$ is the distance fallen, $$g$$ is the acceleration due to gravity, and $$t$$ is time.
  3. Air resistance plays a significant role in free fall when objects are not in a vacuum; it can slow down falling objects and alter their acceleration.
  4. Objects in free fall can be analyzed using graphical representations to show relationships between distance, velocity, and time throughout their descent.
  5. When an object reaches its terminal velocity during free fall, it no longer accelerates because the force of air resistance equals the gravitational force acting on it.

Review Questions

  • How does the concept of free fall illustrate Newton's second law of motion?
    • Free fall exemplifies Newton's second law of motion, which states that the acceleration of an object is dependent on the net force acting upon it and its mass. In free fall, the only force acting on a falling object is gravity, causing it to accelerate downward at a rate of approximately $$9.81 \, m/s^2$$. This showcases how the force of gravity leads to uniform acceleration, confirming the principle that net force equals mass times acceleration.
  • Discuss how understanding free fall can help explain projectile motion.
    • Understanding free fall is essential for analyzing projectile motion since projectiles have both horizontal and vertical components. The vertical component experiences free fall due to gravity while moving downward at an accelerating rate. By separating the two components, one can predict the path and behavior of a projectile using free fall principles for its vertical motion while considering constant velocity for its horizontal motion.
  • Evaluate how free fall principles apply to real-world scenarios such as skydiving or dropping objects from heights.
    • In real-world scenarios like skydiving or dropping objects, free fall principles illustrate key concepts like acceleration, air resistance, and terminal velocity. As a skydiver jumps out of a plane, they initially accelerate downward under gravity until air resistance increases and balances out their weight, reaching terminal velocity. This evaluation highlights how understanding free fall can inform safety measures and predict behavior during such activities based on gravitational forces and aerodynamic factors.