Terminal Velocity

In a free fall, the forces are:

• Weight - downwards
• Drag (air resistance) - upwards

1. Initially, acceleration = $9.81 \unit{m\,s^{-1}}$
   • There is α resultant force downwards
2. When velocity ⬆, drag ⬆
   • resultant force ⬇
   • acceleration ⬇
3. When weight = drag
   • resultant force = 0
   • acceleration = 0   (Follows Newton's Laws of Motion)
   • Terminal velocity reached

Note: Graph of $a$ is not a straight line because resultant force is constantly changing and $a=\frac{F}{m}$