* Gravity: This is the primary force pulling the object downwards. The stronger the gravitational pull, the faster the object accelerates.
* Air Resistance (Drag): As an object falls through the air, it experiences resistance from the air molecules. This resistance increases as the object's speed increases.
* Object Shape and Size: The shape and size of the object significantly affect its air resistance. Objects with larger surface areas and less streamlined shapes experience more drag.
Here's how it works:
1. Initial Acceleration: When an object starts falling, it accelerates due to gravity. The only force acting on it is gravity, so it falls faster and faster.
2. Increasing Drag: As the object falls faster, the air resistance acting on it increases. This drag force acts in the opposite direction to the object's motion, slowing it down.
3. Balance of Forces: Eventually, the drag force becomes equal in magnitude to the force of gravity. At this point, the net force on the object is zero, and it stops accelerating.
4. Terminal Velocity: This constant speed the object reaches when the forces of gravity and air resistance are balanced is called terminal velocity.
Key Points:
* Terminal velocity depends on the object's mass, shape, and the density of the air. A heavier object will have a higher terminal velocity than a lighter object of the same shape.
* Objects with larger surface areas will reach terminal velocity more quickly.
* Terminal velocity is not a fixed value for all objects. It varies depending on the factors mentioned above.
Example:
* A skydiver with a parachute open has a much lower terminal velocity than a skydiver without a parachute. This is because the parachute increases the surface area and air resistance, slowing the descent.
