# Real-life Examples of a Parabola for a Better Understanding

Parabolas are a set of points in one plane that form a U-shaped curve, but the application of this curve is not restricted to the world of mathematics. It can also be seen in objects and things around us in our everyday life. ScienceStruck lists out some real-life examples and their importance, which will help you understand this curve better.

Raksha Kulkarni

Last Updated: Mar 26, 2018

Did You Know?

The path of a object thrown or hurled in the air forms a parabola. The first one to prove that was Galileo. In the early 17th century, he experimented with balls rolling on inclined planes.

Important Terms to Understand

~ A focus of a parabola is a fixed point present on the interior of the curve of a parabola.

~ A directrix is a line perpendicular to the axis of symmetry.

~ An axis of symmetry is the line that passes through the focus and vertex.

~ A vertex is the point on the parabola where the line takes a turn to form the curve.

~ A directrix is a line perpendicular to the axis of symmetry.

~ An axis of symmetry is the line that passes through the focus and vertex.

~ A vertex is the point on the parabola where the line takes a turn to form the curve.

^{2}". Here is a figure to help you understand the concept of a parabola better.

Real-life Applications

Satellite Dish

A satellite dish is a perfect example of the reflective properties of parabolas mention earlier. The signals that are received are directly sent to the focus, which are then correctly reflected to a receiver (signals are sent out parallel to the axis). These signals are then interpreted and are transmitted as channels on our TV. The same principle applies to radio frequencies too. Parabolic mirrors and heaters also work on the same principle.

Headlight

This is the same principle like the one used in a torch. The inner surface is smooth and made of glass which makes it a powerful reflector. The principle used here is that the light source is at the focus, and the light rays will be reflected parallel to the axis. This is the reason one can see a thick focused beam of light emitting from a headlight.

Suspension Bridge

If one is to observe suspension bridges, the shape of the cables which suspend the bridge resemble a parabolic curve. There has been sufficient confusion about whether the cables are suspended in a parabola or a catenary. Studies show that the shape is nearer to a parabola. The cables would have been hyperbolic, but when a uniform load (the horizontal deck) is present, they get deformed like a parabola.

Path of an Object in Air

Take the example of any object thrown up in the air. It goes up in the air till its highest attainable height or point and then comes down back to the ground. If one is to trace the path of the object, the resulting curve obtained is a parabola. The point at which you release the ball and the altitude forms a line (Y axis on a graph). The midpoint of this line is bisected by a perpendicular from the vertex of the parabola. The speed and air resistance might distort the shape sometimes.