osman@sprite.DEC (Eric, DIGITAL, Burlington Ma. 617 273-7484) (10/24/85)
> Since the piece of metal expands uniformly when it is heated, >the hole must expand. If you use a square hole, consider the >portion of the metal that runs along an edge of the square hole. >If this rod-shaped portion of the metal piece was heated by itself, >it would expand in length; so it must also expand in length when it >is part of the hole. Thus, the length of the side of the hole must get >bigger and the hole expands. > > David Moews ...harvard!h-sc1!moews_b moews_b%h-sc1@harvard.arpa > "The Cray-5 can execute an infinite loop in under a minute." Quite an UNconvincing argument. The rod would get fatter too, suggesting it's wideness intrudes into the square, so perhaps the square hole gets *smaller*. /Eric
ron@brl-sem.ARPA (Ron Natalie <ron>) (10/25/85)
Yes and I suspect the reason heating the barrel hoops or wagon wheel rings works is that the thermal expansion is proportional to the length. The circumfrence of the ring is much larger than the thickness so the fattening of the ring is negligable compared to the increase in circumfrence. =ron