The Science Behind Ziplines
The Science Behind Ziplines
Ziplines are an exciting experience for thrill-seeking adventures 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. Gravity on a zipline doesn’t quite have the same effect as it would if you stepped off without a line. Gravity typically pulls directly toward the ground, so when falling on an incline, the acceleration due to gravity decreases. Gravity is a key factor in how fast you will travel on steeper lines.
Friction
Friction is one of the forces that slows you down on the zipline. When ziplining, you travel down the line on a trolley. This trolley has wheels that roll along the metal line because rolling creates less friction than sliding. Without the trolley, you likely would get stuck halfway down the line. And, because the force of friction is greater than the force of gravity.
On some ziplines, stopping at the bottom is also controlled by friction. The riders wear gloves so they can slide their hands along the line as they near the end to slow down. The force between the hand and the line is an example of 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. Check out the science behind ziplines.
air resistance = (constant k)(velocity)2 =(air density)(drag)(area)2(velocity)2
Three factors of this equation: the surface area of the traveling object, the speed of that object along the line, and constants such as air density and drag. The faster an object travels, the more air resistance it experiences. When the air resistance reaches a certain point, that is when the object reaches terminal velocity: the maximum speed of travel for that object in those conditions. Air resistance is always acting against the direction of travel, so you may notice your speed leveling out as you get further down the line.
Gravitational Weight
The key difference in the science behind zipline travel for someone with greater gravitational weight compared to 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. 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 force due to gravity increases. The object can accelerate before reaching terminal velocity and leveling off.
Author: Michelle Patten
