Friction and Terminal Velocity

Friction is a resisting force that acts between surfaces in contact to oppose motion.
Friction depends on the types of surfaces in contact and the force pressing these surfaces together.
It can cause a moving object to slow down and eventually stop.
Friction can be classified into static friction (between stationary objects) and kinetic friction (between moving objects).
Frictional forces are parallel to the contact surface between objects and in the opposite direction to the movement.

An object falling under gravity experiences a drag force, also known as air resistance. This force works in the opposite direction of the motion.
Initially, gravity makes it accelerate, but as its speed increases, so does the drag force.
At a certain speed, the drag force equals the force due to gravity, and the object no longer accelerates. It continues to fall at a constant speed, known as the terminal velocity.
The terminal velocity of an object depends on its size, shape, and mass. A large or heavy object will have a higher terminal velocity than a small or light one.

Understanding friction is crucial for various everyday applications, like braking in vehicles, walking, and designing any system where two surfaces interact.
The concept of terminal velocity is instrumental in understanding free-falling objects’ behaviour, such as parachutists.
Manipulating variables, like size and shape, allows humans to control how quickly objects reach terminal velocity, which can be key in designing safety gear and equipment.