The Science Behind Ziplines
The Science Behind Ziplines
Ziplines are an exciting experience for thrill-seeking adventurers and are also a speedy, efficient means of travel between two points on a downward slope. But how exactly do ziplines do their job? Let’s take a look at the science behind ziplines.
Gravity
Gravity is the essential force that moves you down the zipline. Without gravity, when you step off a platform, you wouldn’t be going anywhere. The effect of gravity changes when you’re on an incline: gravity pulls straight down, but only part of this pull moves you along the sloped zipline. The steeper the incline, the greater the portion of gravity that accelerates you along the line, making you travel faster.
Friction
Friction is one of the forces that slows you down on the zipline. When ziplining, you travel down the line on a trolley with wheels that roll along the metal cable, reducing friction compared to sliding. Without wheels, friction could become stronger than gravity, and you would likely get stuck halfway down the line.
On some ziplines, friction also helps stop you at the bottom. Riders wear gloves to slide their hands along the line as they near the end and slow down. The force between the hand and the line is friction.
Air Resistance
Air resistance is another force that slows you down on the zipline. A lot of factors go into the air resistance that you experience while traveling down the line. To understand these factors, check out the science behind ziplines.
air resistance = (constant k)(velocity)2 =(air density)(drag)(area)2(velocity)2
Three factors affect air resistance on a zipline: the size of the moving object, its speed, and the air conditions. The faster you go, the more the air pushes against you. When this push gets strong enough, you stop getting faster. This is called your top speed. Air is always pushing against your movement, so you might notice your speed stays the same as you go farther down the line.
Gravitational Weight
The key difference in the science of zipline travel between someone with greater mass and someone lighter involves air resistance and terminal velocity. You may notice that the air resistance equation above says nothing about the mass of the traveling object. The air resistance someone experiences does not depend on their weight. An object’s terminal velocity does.
Terminal velocity occurs when the force of air resistance equals the force of gravity. Gravity: F = mg is the force due to gravity. M is the mass of the object, and g is the acceleration due to gravity, which is essentially a constant on a fixed line.
As an object gets heavier, its gravitational force increases, allowing it to accelerate until it reaches terminal velocity and begins to level off.
Author: Michelle Patten
