text: what are the different uses of a parabola?   parabolae show up everywhere in the world around us. for example:  1. the reflecting mirror at the back of a headlight is a parabola.   2. parabolae are used to describe the trajectories of projectiles.   3. satellite dishes are parabolae.   4. the surface of a fluid that is being rotated is a parabola.   5. the microphones used to pick up distant sounds, like those on a football field, have a parabolic reflector behind them.   6. the equation for the stopping distance of a car as a function of speed is a parabola.   7. while the shape of a hanging cable between two poles is a catenary, but the shape of the cable holding up a suspension bridge is actually a parabola.   8. the velocity as a function of radius in a pipe is a parabola.   9. under some conditions, orbits of meteors, comets, etc are parabolae.  10. radio telescopes are shaped like parabolae  and many others.