Forces: Terminal Velocity

Terminal velocity is the highest speed an object will reach when falling through a fluid, like air or water.
It occurs when the drag force (force opposing the motion) equals the gravitational force pulling the object downwards.
At this point, there is no acceleration, as the forces are balanced, meaning the velocity of the object becomes constant.
The value of terminal velocity depends on the shape, size, and mass of the object, as well as the density of the fluid it is falling through.

Drag force, also known as air resistance, opposes the motion of an object.
The amount of drag force depends on the speed of the object. The faster an object moves, the greater the drag force.
The object’s surface area also directly impacts the drag. Larger surface areas experience more drag force.

Initially, when an object first falls, it accelerates due to gravity, and there is little air resistance.
As speed increases, the air resistance increases until it is equal to the weight of the object.
At this point, terminal velocity is reached, and the object falls at a steady speed.

Mass: Heavier objects have a greater terminal velocity.
Shape and Size: Streamlined objects face less air resistance, resulting in a higher terminal velocity than less aerodynamic objects. Similarly, smaller objects experience lesser drag.
Density of the Fluid: The denser the fluid, the greater the drag force, reducing terminal velocity.

On a velocity-time graph for an object falling at terminal velocity, the flat, horizontal line represents terminal velocity.
The steep part at the start of the graph represents the acceleration phase where the object is gaining speed.
The point where the graph starts to level off, indicating the object’s speed is no longer increasing, is when terminal velocity is reached.