Flag Pole

talzamir

Art, not a Toil

Posers and Puzzles

24 Oct 11

talzamir

Art, not a Toil

60.13N / 25.01E

Joined: 19 Sep 11
Moves: 59234

24 Oct 11

A flagpole has diameter of 10 centimeters (4"😉. A rope that is 10 meters (30'😉 long has been attached to the top. It spirals around the flagpole 25 times before the other end of the rope reaches the ground. How tall is the flag pole?

forkedknight

Defend the Universe

127.0.0.1

Joined: 18 Dec 03
Moves: 16687

24 Oct 11

1 edit

I get

talzamir

Art, not a Toil

60.13N / 25.01E

Joined: 19 Sep 11
Moves: 59234

24 Oct 11

I wonder why the answer I got is exactly 25 times yours..? And that does make the respectable-sized flagpole I had in mind..?

mtthw

Joined: 07 Sep 05
Moves: 35068

24 Oct 11

1 edit

I agree with forkedknight's answer:

,
where L = length of rope and d = diameter.

forkedknight

Defend the Universe

127.0.0.1

Joined: 18 Dec 03
Moves: 16687

24 Oct 11

2 edits

Originally posted by talzamir
I wonder why the answer I got is exactly 25 times yours..? And that does make the respectable-sized flagpole I had in mind..?

25 times what i got is 15x longer than your rope...

*edit* I see your response was before I did my edit, and my edit added the multiplier of 25 that i missed in my initial calculation (I broke the flag pole up into 25 rectangles across which the rope makes the hypotenuse)

talzamir

Art, not a Toil

60.13N / 25.01E

Joined: 19 Sep 11
Moves: 59234

24 Oct 11

So we both multiplied by 25? That makes a very awesome flagpole. ^_^ So yes, a bit over six meters it is.