Applications of Parabolas

Here are the formulas to compute those distances:

Note that both the braking distance and the total stopping distance formulas are quadratic, and therefore their graphs are parabolas.

2. Heater         Heaters are sold which make use of the relection property of the parabola. The heat source is at the focus and heat is concentrated in parallel rays. Have you walked by the parabolic reflector heater at COSTCO? 3. Satellite Dishes         Satellite Dishes work on this same principle. Incoming waves are concentrated to the focus. 4. Automonbile Headlights         An automobile headlight is another example of a Paraboloid of Revolution --         taking a parabola and rotating it about its axis of symmetry.         The smooth inner surface of the headlight is a glass reflector upon which         bright aluminum has been deposited. This part is a powerful reflector.         A parabolic reflector has the property that if a light source is placed at the         focus of the reflector, the light rays will reflect from the mirror as rays         parallel to the axis.         This is used in auto headlights to give an intense concentrated beam of light.         For safer night driving, we do not want all the light rays to be parallel         to the axis. Some light must be aimed far down the road, to the side, upward         for signs or bridges.         So we offset the filament from the focus and change the beam entirely.         In most of today's cars, a 4 Lamp System is used -- 2 filament sealed beam         units in 2 lamps.         The position of the filaments accomplishes most of the desired illumnination         patterns. The rest is taken care of by special lenses which contain prisms         to bend the light rays. 5. Comic Strips         Look at the poor guy in this comic strip with his parabolic reflectors! Watch out who you get for your insurance company!         Watch out for Parabolic Microphones -- you never know who is listening! 6. McDonald's Arches         McDonald's Arches are parabolas. 7. Fountains         Bellagio's fountains at Las Vegas exhibit water in the shapes of parabolas. 8. Path of a Ball         Gallileo was the first to show that the path of an object thrown in space is a parabola. 9. Golden Gate Bridge         The cables that act as suspension are parabolas. 10. Le Four Solaire at Font-Romeur         There is a reflector in the Pyrenees Mountains that is 8 stories high.         It cost two million dollars to build and it took ten years to build it.         It is made of 9,000 mirrors arranged in a parabolic mirror.         It can reach 6,000 degrees Fahrenheit just from the Sun! 11. Parabolic mirror         A parabolic mirror at the Seattle Science Museum. 12. Parabolic Receivers         A person who whispers at the focus of one of the parabolic reflectors can be heard by a person located near the focus of the other parabola.