Terminal Velocity

Definition

Terminal velocity is the constant speed that a freely falling object eventually reaches when the resistance of the medium through which it is falling prevents further acceleration. This balance occurs when the force of gravity pulling the object downward equals the drag force acting against it, resulting in a net force of zero. At this point, the object continues to fall at a steady speed, which is crucial for understanding motion in fluids and how forces like friction and drag impact falling objects.

5 Must Know Facts For Your Next Test

1. Terminal velocity varies based on the object's shape, size, and mass, as well as the density of the fluid it's moving through.
2. For a skydiver in a belly-to-earth position, terminal velocity is typically around 53 m/s (about 120 mph), while a head-down position can increase this speed significantly.
3. The process of reaching terminal velocity happens quickly, often within just a few seconds of free fall.
4. Air resistance increases with speed, which is why an object falls faster until it reaches terminal velocity when the upward drag force balances out gravitational pull.
5. In a vacuum, where there is no air resistance, objects will continue to accelerate without ever reaching terminal velocity.

Review Questions

• How does terminal velocity demonstrate the balance of forces acting on a falling object?
  • Terminal velocity showcases how forces interact by demonstrating that as an object falls, gravity pulls it downward while drag force opposes this motion. When these two forces become equal, the net force is zero, resulting in no further acceleration. This state means that although gravity continues to act on the object, it falls at a constant speed known as terminal velocity, reflecting a dynamic balance in physics.
• Discuss how different factors affect an object's terminal velocity and give examples.
  • An object's terminal velocity can be influenced by its mass, shape, surface area, and the medium it's moving through. For instance, a heavier object will generally have a higher terminal velocity than a lighter one because it experiences greater gravitational force. Additionally, a streamlined shape reduces drag force compared to a more irregular shape. For example, a skydiver falling belly-first has a lower terminal velocity than one diving head-first due to increased air resistance against their body.
• Evaluate how understanding terminal velocity can impact safety measures in activities such as skydiving or bungee jumping.
  • Understanding terminal velocity is essential for ensuring safety in activities like skydiving and bungee jumping. By knowing the terminal velocities involved, jumpers can make informed decisions about parachute design and deployment timing. For instance, parachutes are designed to open at specific altitudes to reduce speed effectively and ensure a safe landing. Additionally, knowledge of terminal velocity helps in designing bungee cords that can stretch safely without causing excessive deceleration forces during jumps.

Related terms

Drag Force: The resistance force that acts opposite to the direction of an object’s motion through a fluid, such as air or water.

Free Fall: The motion of an object when it is falling solely under the influence of gravity, with no other forces acting on it.

Acceleration Due to Gravity: The rate at which an object speeds up as it falls towards the Earth, approximately 9.81 m/s² near the Earth's surface.