why are fire engines traditionally red?
454908
because red is a traditional "LOOK OUT WARNING" color
804004
Perhaps it is because red light has the least energy of all the colors of the visible spectrum.  It has the longest wavelength, thus the slowest frequency, slower than that of blue or violet, for example.  I don't know for sure if this is the reason the materials are not sensitive to it, though.
669202
Red? Id' prefer white.
47214
There are 2 tyoes of commonly available diesel fuel, number 1 and number 2.  The one is generally for far use and the other is for comercial highway use.  The red dye is in it because number one is higher in sulfer, and generally cheaper, and not intended for highway use.  There is actually a fine for having fuel with red dye in in found in a big truck.  Thats why the dye is in it.
42096
Fire is what is called a "redox reaction."  This is where atoms exchange electrons, truning high energy bonds into low energy bonds (or orbitals).  Every redox reaction needs an oxidizer (which takes electrons) and a reducer (which gives up electrons).  In a normal fire, oxygen acts as the electron-accepter.  Carbohydrates (wood, sugar, oil, coal, etc) usually acts as the reducer (ie the electron donor).\n\nO2 takes away electrons and becomes CO2, meaning that the oxygen gets consumed in the burning process.  So really, both the oxygen and the fuel are burning, because they both release energy and end up changed by the process.
219455
because blood is blue.\n\nit only turns red when it oxidates/coagulates with oxygen.
977182
Who cares, all flames are hot.\n\n"The color and temperature of a flame are dependent on the type of fuel involved in the combustion."
241318
There's a reason why red lining is considered bad. It will seriously wears down the rings, and the excessive heat will quickly break down the lubrication and oil. Your engine will let you know how much damage you did to it by the amount of smoke you see out of your exhaust.
622473
Red, because it is a live color. Outgoing!
997645
Yes, the vehicle code states what color, size and power of lighting you can have on a motor vehicle, and in what direction they can be aimed.  Blue and red to the front are reserved for emergency vehicles.
4677
Im not certain what you want to know about gas engines.  The most common gas engine is a four stroke internal combustion engine. Let us start the cycle with the piston head top dead center. The intake valve is open and head drops pulling gasoline and air into the cylinder(1st stroke). Next the valves close and due to the rotating crank the piston rises compressing the gas and air(2nd stroke). The sparkplug inites the gas, forcing the piston down (3rd stroke). This explosive force is what moves the car forward. The piston head rises expeling the burnt gas through the exhast valve (4th and last stroke). This leaves the piston in the top dead center position to start the cycle all over again. A car will generaly have four or more cylinders in even numbers (4,6,8, ect.).  while 1st cylinder might be in the 3rd stroke powering the crank shaft, the crank shaft would rotate the other pistons resulting in cylinders 2-4 to experince the strokes (cylinder 2: 4th stroke, cylinder 3: 1st stroke, and cylinder 4: 2nd stroke). Thus there is always one cylinder powering the other cylinders. An eletric starter is used to rotate the crank shaft to intiate the first combustion stroke.  Otherwise how will the pistons move without the intial spark.  Think of the old Ford model T cars and how they had to manualy crank the engine and think of how modern cars start with only a crank of the ignition key. To learn more I recomend researching physics, chemistry, mechanical dynamics, and thermodynamics
95627
i have study about this before 3 yrs but i will check my memory. this engine is called so because the fuel is burnt inside the combustion chamber means internally.it consists of a combustion chamber having an inlet valve so that fuel can enter inside the chamber and an outlet valve to forward the burnt fuel to the other stage. it also consist the piston which is one of the main parts of the engine without it we cant rotate the wheels. piston is also is in a closed cylinder which also have two valves andperform the same functions as they do in comb. chamb. after piston there is another cylinder which is used to throw out the exhausted fuel outside. i think this is enough
538057
inside the nozzle opening there is a color coded piece of plastic, if you can look directly at it while it is actively spraying you can tell the potency. red=still good.
406696
Because it's not red!
990503
The Basics\nWhen most people think about motors or engines, they think about rotation. For example, a reciprocating gasoline engine in a car produces rotational energy to drive the wheels. An electric motor produces rotational energy to drive a fan or spin a disk. A steam engine is used to do the same thing, as is a steam turbine and most gas turbines.\n\nRocket engines are fundamentally different. Rocket engines are reaction engines. The basic principle driving a rocket engine is the famous Newtonian principle that "to every action there is an equal and opposite reaction." A rocket engine is throwing mass in one direction and benefiting from the reaction that occurs in the other direction as a result.\n\nA rocket engine is generally throwing mass in the form of a high-pressure gas. The engine throws the mass of gas out in one direction in order to get a reaction in the opposite direction. The mass comes from the weight of the fuel that the rocket engine burns. The burning process accelerates the mass of fuel so that it comes out of the rocket nozzle at high speed. The fact that the fuel turns from a solid or liquid into a gas when it burns does not change its mass. If you burn a pound of rocket fuel, a pound of exhaust comes out the nozzle in the form of a high-temperature, high-velocity gas. The form changes, but the mass does not. The burning process accelerates the mass.\n\nAnd that is how the rocket moves foward
995583
The red color is found in many soils around the world.\nThe cause of that is the presence of oxides and hydroxides of Fe and Al.\nThose soils are known as ''weatherized'', usually done by many, many years of exposure to heat and humidity.
71769
Brake discs glow red as a result of friction. The brake pads rub on the brake disks and the friction is what causes the vehicle to stop. This friction also in turn causes a great deal of heat to build up and this heat is transfered to the brake discs causing them to glow red. Usually this will only happen in racing vehicles unless there is some problem.