Parabola Facts for Kids

A parabola

Parts of a parabola

A parabola obtained as the intersection of a cone with a plane parallel to a straight line on its surface

The parabola (from the Greek παραβολή) is a type of curve. Menaechmus (380–320 BC) discovered the parabola, and Apollonius of Perga (262 BC–c190 BC) first named it.

A parabola is a conic section. If a cone is dissected by a plane which is parallel to one of the surfaces of the cone, the result is a parabola. The point where the parabola reaches its maximum or minimum is called the "vertex." At this point the curvature of the parabola is greatest.

Each parabola has a focal point. Any ray that enters the parabola and is parallel to the axis of symmetry will pass through this point after being reflected by the curve. Because of this fact, parabolas are important in devices such as satellite dishes, or magnifying mirrors. Parabolas are often used to approximate curves that are more difficult to model by themselves.

Every parabola uses the equation $y = ax^2 + bx + c$ , where $a$ , $b$ and $c$ are constants, and $a$ is not equal to $0$ .

Images for kids

Parabolic compass designed by Leonardo da Vinci
Perpendicular from focus to tangent
Sector area proposition 30
Quadratic Bézier curve and its control points
Elliptic cone
Parabolic cylinder
Elliptic paraboloid
Hyperbolic paraboloid
Hyperboloid of one sheet
Hyperboloid of two sheets
A bouncing ball captured with a stroboscopic flash at 25 images per second. The ball becomes significantly non-spherical after each bounce, especially after the first. That, along with spin and air resistance, causes the curve swept out to deviate slightly from the expected perfect parabola.
Parabolic trajectories of water in a fountain.
The supporting cables of suspension bridges follow a curve that is intermediate between a parabola and a catenary.
The Rainbow Bridge across the Niagara River, connecting Canada (left) to the United States (right). The parabolic arch is in compression and carries the weight of the road.
Parabolic arches used in architecture
Parabolic shape formed by a liquid surface under rotation. Two liquids of different densities completely fill a narrow space between two sheets of transparent plastic. The gap between the sheets is closed at the bottom, sides and top. The whole assembly is rotating around a vertical axis passing through the centre. (See Rotating furnace)
Solar cooker with parabolic reflector
Parabolic antenna
Parabolic microphone with optically transparent plastic reflector used at an American college football game.
Array of parabolic troughs to collect solar energy
Edison's searchlight, mounted on a cart. The light had a parabolic reflector.
Physicist Stephen Hawking in an aircraft flying a parabolic trajectory to simulate zero gravity

Parabola facts for kids

Images for kids

See also