Brain Teaser for fun ... yes I have the answer?

Question

Please don't accuse me of asking you to do my homework. I have the answer to this question and am only posting it for fun:

Consider a perfectly rectangular room 12 ft high, 12 ft wide, 30 ft long. A spider is in the middle of one end wall, 1 ft from the ceiling. A fly is in the middle of the opposite wall, 1 ft from the floor and paralyzed with fear.

What is the shortest distance the spider must crawl along the walls, ceiling and/or floor in order to reach the fly.

Both the fly and spider are on the walls that measure 12 x 12 but are at opposite ends of the room. Both are 6 ft away from the walls; the spider 1 ft from the ceiling, the fly 1 ft from the floor. Sorry, thought it was clear.

And so far, neither of you have the right answer.

Noone has the correct answer in the first 8 guesses. Though the idea that he dropped to the ground and only crawled 31 ft is the most creative so far.

If noone gets the right answer, Scott R. gets it.

Well done pascal!!! You got it. Check this link for a diagram that is easier to understand:

http://mathworld.wolfram.com/SpiderandFlyProblem.html

Scott: You had a good answer. But I thought Pascal had the best answer. You would have had it if he didn't give his answer. :-)

Answer 1

40 feet. Unfold the walls of the room to make a tessarect like this (note that this drawing is not to scale):

..--
..--+
..--
+--

Where -- is one of the long walls and + is one of the square walls at the end. The -- on the bottom of this tessarect is supposed to be the floor, and the + on the left the wall the fly is on. The ..s are placeholders. Anyway, once you have drawn this tessarect, simply connect the points with the fly and the spider with a straight line. This line spans 32 feet horizontally and 24 feet vertically, for a total distance of √(32²+24²)=40 feet. This line corresponds to a route around the floor, wall, and ceiling at about 36.87°, which is actually shorter than the naive route along the middle of the floor (which is 42 feet). Trying this strategy with all possible tessarect reveals that this 40 ft. route actually is the shortest one.

Answer 2

The fly is paralyzed with fear, yet not necessarily from the spider. Assuming paralysis is not permanent, a fly in fear would take flight -- continuously seeking an escape route -- though a perfectly rectangular room (rectangular prism?) might not have one. So eventually, the fly would end up caught in the spider's web (it is generally invisible to insects -- sometimes, to people, also!). The shortest distance, therefore, would not exceed the length of the spider's longest leg (all eight could be the same length). The spider -- already sitting (or standing?) on his web may not have to move at all. Consistent with the unit of length given in this problem, the answer must be 0 feet.

Answer 3

31 feet after it drops to the floor and crawls along the 30 ft floor and 1 foot of wall.

Hey, what about
"A twist to the problem can be obtained by a spider that suspends himself from strand of cobweb and thus takes a shortcut by not being forced to remain glued to a surface of the room. If the spider attaches a strand of cobweb to the wall at his starting position and lowers himself down to the floor (thus not crawling a single inch), he can then cross the length of the room by foot () and ascend a single foot, thus reaching his prey after a total crawl of 31 "

Same as mine,essentially.
You asked for a minimum, and did not preclude this answer in your question.

Answer 4

42 ft

Answer 5

Is that still "the shortest distance between 2 points is a straight line," but applied to 3D instead of 2D? Is that what a tessarect is good for?

Oh, Pascal already answered it. GOOD ONE!

Answer 6

If they are both in the middle of the long wall (the 30ft wall) then the distance is 24ft


If they are both in the middle of the short wall (the 12ft wall) then the distance is 44ft

Answer 7

Missile one strikes at 9000 mph, or one hundred fifty miles consistent with minute. Missile 2 strikes at 21000 mph, or 350 miles consistent with minute. So one minute in the previous they collide they are one hundred fifty + 350 = 500 miles aside.

Answer 8

24 ft.

Answer 9

down the wall and across the floor

Answer 10

19 ft, you didn't say if it was the far end or not.