Mainly the head but also the neck muscles which support the head.
When you hit your head your nervous system tells your brain that you are in pain.
Actually three: the skin, nervous system and the skeletal system.
There are many different systems involved in an automobile, be more specific.
Every action has an equal and opposite reaction. When something hits you from behind that is travelling even slightly faster then you, the energy comming from all of the 4000lbs in motion that hit you is transfered into your car. Your car lurches forward transfering some of that energy into your body. A body at rest stays at rest. Your head was stationary until your body lurched forward with the rest of your car. Your head has to catch up to the rest of your body and you end up damaging the soft tissue in and around your head neck and shoulders. Get hit hard enough and you can break your neck. If your head is against the head rest, the head rest will move your head forward at the same time as the rest of your body is moved forward by the seat. This will keep your head from snapping backwards.
Yes, it is a very involved project on a car with very little room under the hood.
Nobody killed her, Lisa died of severe head trauma after being involved in a car accident.
That would depend on how many vehicles are involved. If only two vehicles are involved, and they both stop after the crash, then there is one collision That's not what is meant. There is ALWAYS more than one collision when a car crashes. There are THREE (3) collisions in every crash. The car itself hitting the other car; your body hitting the dash or other part of the car depending on where you're sitting; and finally the collision that is inside the body, your organs and bones hitting against the inside of your body.
It refers to the frame, engine,front and rear axles, springs, steering systems and the fuel tank bolted directly to the body-in short everything but the body.
I take it you mean the head gasket. Head gaskets are pretty cheap, but the labor is high. If it is a V 6 or V8 you may have to do only one side. A lot would depend on what engine you have. I don't know if it is a car, boat or what, so it is hard to say what all is involved. You do have to remove the head from the engine to install a head gasket.
The earth cable from the car to the steering column has broken, so put a cable from the column to the car body.
There are generally 3 types of cars at the head of a atrain. The car at the head end of a train is most oftena locomotive, but it can also be a "cab car", which has a cabin for the train operator/motorman/engineer, but is not a locomotive. For many transit systems, this car may be a Multiple Unit (MU) or Electrified MU (EMU) car. In most cases, when a freight train is seen with a freight car at the head of the "train", under US law, this is most often not termed a train, but a "consist" - this is because it fails to have the markers necessary to move legally as a train.
One can find information on car security systems from the Yahoo! Voices article titled "5 Best Car Alarm Systems Money Can Buy." This article provides more information on different car security systems.