- Block stacking problem
In
statics , the block stacking problem (also the book stacking problem, or a number of other similar terms) is the following puzzle:Place N
rigid rectangular blocks in a stable stack on a table edge in such a way as to maximize the overhang.The single-wide problem involves having only one block at any given level. In the ideal case of perfectly rectangular blocks, the maximal overhang tends to
infinity as N increases.The solution to the single-wide problem is that the maximum overhang is given by sum_{i=1}^{N}frac{1}{2i} times the width of a block.
Multiwide stacks using counterbalancing can give larger overhangs than a single width stack. Even for three blocks, stacking two counterbalanced blocks on top of another block can give overhang close to 1, while the overhang in the simple ideal case is at most 11/12. As harvtxt|Paterson|Peres|Thorup|Winkler|2007 showed, asymptotically, the maximum overhang that can be achieved by multiwide stacks is proportional to the cube root of the number of blocks, in contrast to the single-wide case in which the overhang is proportional to the logarithm of the number of blocks.
Paterson et al. provide a long list of references on this problem going back to
mechanics texts from the middle of the 19th century.harvtxt|Hall|2005 discusses this problem, shows that it isrobust to nonidealizations such as rounded block corners and finite precision of block placing, and introduces several variants including nonzerofriction forces between adjacent blocks.References
*citation
first = J. F. | last = Hall
title = Fun with stacking blocks
journal = American Journal of Physics
volume = 73 | issue = 12 | year = 2005 | pages = 1107–1116.
*citation
last1 = Paterson | first1 = Mike
last2 = Peres | first2 = Yuval
last3 = Thorup | first3 = Mikkel
last4 = Winkler | first4 = Peter
last5 = Zwick | first5 = Uri
title = Maximum overhang
year = 2007
id = arxiv|0707.0093.External links
*
Wikimedia Foundation. 2010.