Joke: The Engineer and the Princess

It's been while sense I heard that one. Here is a better one =)
A mechanical engineer, an electrical engineer and a software engineer are traveling in an old car when all of the sudden the car backfires and comes to a halt.
The mechanical engineer says "Ah! It's probably a problem with the valves, or the piston!".
The electrical engineer says "Nonsense! It's most probably a problem with the spark plugs or the battery!".
The software engineer says "How about we all get out of the car, and get back in again".

OR this one: A mathematician, a physicist and an engineer go to a bar. The barman is a bit of a joker (and knows a little maths) and sets them this challenge:

A pint of beer is placed on the bar, and a line drawn 2 m away from and parallel to the bar.

"Now," says the barman, "You start from this line, and you can only take steps towards the bar that are half the remaining distance between you and the bar."

The mathematician and the physicist take mere seconds to work this one out, and sit back on their bar stools. "Can't be done." says the mathematician. "You can never reach the bar." says the physicist.

The engineer stands at the line, takes four (ever decreasing) steps towards the bar, reaches out and picks up the pint. "Close enough for me," he comments, before downing the pint.

For some odd reason there are a ton of engineer jokes that make fun of mathematicians and physicists. I think it has to do with the fact we have to build the things they tell us are impossible.