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Understanding the Current Year's Lofting Rules

← Builds on Analyzing a Still-Air Flight Log

Terms you will need

  • terminal velocityThe fastest speed an object can reach when falling through air, where the force pulling it down is balanced by the air pushing up.
  • drag forceThe force that air or fluid exerts on an object moving through it, pushing against the direction of motion.
  • parachute canopy areaThe size of the parachute's surface that catches air to slow down the fall.
  • shroud linesThe lines that connect the parachute to the object or person it is protecting, helping to control the parachute's shape and stability.
  • coefficient of dragA number that shows how much air resistance an object experiences based on its shape and how it moves.
  • fall timeThe amount of time it takes for an object to fall from a certain height to the ground.

How this topic runs

  1. 1Start here
  2. 2How it works

The key concept to grasp is terminal velocity, which is the maximum speed an object can reach as it falls through a fluid like air. This speed is determined by the balance between the force of gravity pulling the object down and the drag force resisting its motion.

At this point, the force pulling the object down (gravity) is exactly balanced by the force pushing up (air resistance or drag). This balance means the object stops speeding up and keeps falling at a steady speed. The object's shape and size matter a lot.

A parachute, for example, has a large surface area and low mass, so it reaches a low terminal velocity. A dart, with a small surface area and higher mass, reaches a much higher terminal velocity. This is why a skydiver in a spread-out position falls slower than one in a head-down position.

The rock speeds up more before air resistance balances gravity. Both eventually fall at a constant speed, but the rock’s is much faster. Understanding terminal velocity helps explain why small animals like mice can survive big falls.

Their size means air resistance is strong enough to slow them down before they hit the ground. People, on the other hand, fall too fast for air to stop them safely.

Key Points

  • Terminal velocity is the maximum speed attainable by an object as it falls through a fluid, reached when the sum of the drag force and buoyancy equals the downward force of gravity.
  • Drag force is a force acting opposite to the direction of motion of any object moving with respect to a surrounding fluid, and it depends on velocity, increasing with the square of the speed for high-speed flow.

Terms

Tap a term for a plain-language explanation.

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