You are given a single long rope of length L (ft) with radius R (in), a very sharp knife, and 2 matches. Your task is to completely burn the rope in the minimum amount of time.
Calculate the total time required to burn the rope.
Details:
- The rope is considered stiff with a minimum bend radius of 10*R
- The rope is tightly woven with many fibers and may be considered to have a solid cross section
- You may cut the rope into more than one piece
- The rope burns at R in/min
- A match will light the rope instantaneously and will burn out as soon as the rope is touched
- Assume gravity
- Ropes in contact can transfer fire immediately to one another at the contact point only, but will themselves continue to burn at the constant specified burn rate
- Static structures
- The matches dimensions are 4R x R/4 x R/4
Be creative
Hints:
- Think about 3D structures
- Due to gravity a structure should be able to hold it's shape
- Determine the burn rate per unit volume of rope material
- Consider the shape of the structure sub-elements and how they transfer fire to one another