There are several. If you are asking where to add water or coolant, most have a cap on the top of the radiator which is in the front of the car right behind the grill. Some have a reservoir or bottle on the inside fender. This may be on either side depending on the type of car. It should be marked Coolant Only. In either case, they should only be opened and coolant added when they are cool.
There are no water pipes passing through the interior cabin of a car.
Snow, watr, or ice getting into your exaust pipe then it melts...
Nothing
your head could be cracked you will not notice the water lose when you car is running see if the water is coming out of the tale pipe
Its water in the gasoline mixture. When the car is first started, the engine temperature is not high enough to evaporate the water in the gas, so the water travels out the exhaust pipe
Hot water pipe rust first as compared to the cold water pipe for the same chemical composition of the water.
Yes, as long as the water coming out of the pipe has a greater pressure than the water that is covering the pipe. If it is the other way around, the water covering the pipe will actually flow into the pipe. Think about it. It just makes sense.
Supply coming from water source is a water service line.
A water pipe.
Cold water pipe.
Not with air! Run water in pipe at highest elevation of pipe and see that water drains at end of pipe system.
if it is losing it thru the overflow pipe you need a new radiator cap