hopp@nbs-amrf.UUCP (Ted Hopp) (11/07/85)
Inspired by a problem posted to net.physics, I dug this up.
From the UCLA Engineering Student Newsletter (sometime in the dark ages):
A rope over the top of a fence has the same length on each side.
Weighs 1/3 lb. per ft. On one end hangs a monkey holding a banana, and
on the other end a wt. equal to the wt. of the monkey. The banana
weighs 2 oz. per inch. The rope is as long as the age of the monkey,
and the wt. of the monkey (in ounces) is as much as the age of the
monkey's mother. The combined ages of monkey and mother are 30 years.
1/2 the wt. of the monkey, plus the wt. of the banana, is 1/4 as much
as the wt. of the wt. and the wt. of the rope. The monkey's mother is
1/2 as old as the monkey will be when it is 3 times as old as its
mother was when she was 1/2 as old as the monkey will be when it is as
old as its mother will be when she is 4 times as old as the monkey was
when it was twice as old as its mother was when she was 1/3 as old as
the monkey was when it was as old as its mother was when she was 3
times as old as the monkey was when it was 1/4 as old as it is now.
How long is the banana?
--
Ted Hopp {seismo,umcp-cs}!nbs-amrf!hopplatham@bsdpkh.UUCP (Ken Latham) (11/15/85)
> A rope over the top of a fence has the same length on each side. > Weighs 1/3 lb. per ft. On one end hangs a monkey holding a banana . . . > How long is the banana? > > Ted Hopp {seismo,umcp-cs}!nbs-amrf!hopp the answer ,I believe, is 4.5 inches! which is large for a monkeys' banana, but just the same, he shouldn't be holding it in public! the solution is straight forward once you unravel the last sentence. I won't expalin it here, that would take all of the fun out of the puzzle! Ken ( the wonderkin of the 90's ) " A critter in every pot! " PS I am almost positive the answer is correct as the mathematics of working it out were somewhat akin to those of the GRE. ( i.e. simple math -- difficult (if not, simply confusing ) concept ) -- Concerning those who have a great deal of experience: " There are those who have many experiences... and those who have one experience many times." _______________________________________________________________________________ | | | | Ken Latham | uucp: ihnp4!bsdpkh!latham | | AT&T-IS | uucp: {ihnp4!decvax,peora}!ucf-cs!latham | | Orlando , FL | arpa: latham.ucf-cs@csnet-relay | | USA | csnet:latham@ucf | |_____________________________|_______________________________________________|
ags@pucc-h (Dave Seaman) (11/25/85)
In article <149@bsdpkh.UUCP> latham@bsdpkh.UUCP (Ken Latham) writes: >> A rope over the top of a fence has the same length on each side. >> Weighs 1/3 lb. per ft. On one end hangs a monkey holding a banana > . > . > . >> How long is the banana? >> >> Ted Hopp {seismo,umcp-cs}!nbs-amrf!hopp > > >the answer ,I believe, is 4.5 inches! I don't think you back-substituted to see whether your answer made sense, because it doesn't. It works much better if the banana is 5.75 inches long. Hint: The monkey is 12 years old. -- Dave Seaman {decvax|harpo|ihnp4|inuxc|seismo|ucbvax}!pur-ee!pucc-h!ags
langer@lasspvax.UUCP (Stephen Langer) (11/27/85)
In article <2484@pucc-h> ags@pucc-h.UUCP (Dave Seaman) writes: >In article <149@bsdpkh.UUCP> latham@bsdpkh.UUCP (Ken Latham) writes: >>> A rope over the top of a fence has the same length on each side. >>> Weighs 1/3 lb. per ft. On one end hangs a monkey holding a banana >> . >> . >> . >>> How long is the banana? >>> >>> Ted Hopp {seismo,umcp-cs}!nbs-amrf!hopp >> >> >>the answer ,I believe, is 4.5 inches! > >I don't think you back-substituted to see whether your answer made sense, >because it doesn't. It works much better if the banana is 5.75 inches >long. Hint: The monkey is 12 years old. >-- >Dave Seaman {decvax|harpo|ihnp4|inuxc|seismo|ucbvax}!pur-ee!pucc-h!ags No, you're all wrong. This is a physics problem. The rope has the same length on each side; the weight on one side weighs the same as the monkey on the other; the top of the fence is frictionless; the system is in equilibrium; therefore the banana is massless, or the system would not balance. The length of the banana is zero. I don't know if this is consistent with the rest of the problem as stated. I didn't try to work it out. -- 0)) ((0 0 __ <|..|> :0_ _0: \/ / \ \ / ---||- || Steve Langer /\ Physics Department, Clark Hall / \ Cornell University _\ \_ Ithaca, NY 14853 {ihnp4,decvax,allegra,vax135}!cornell!lasspvax!langer
ags@pucc-h (Dave Seaman) (11/30/85)
>>>> A rope over the top of a fence has the same length on each side. >>>> Weighs 1/3 lb. per ft. On one end hangs a monkey holding a banana >>> . >>> . >>> . >>>> How long is the banana? > >No, you're all wrong. This is a physics problem. The rope has the >same length on each side; the weight on one side weighs the same as >the monkey on the other; the top of the fence is frictionless; the ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >system is in equilibrium; therefore the banana is massless, or the >system would not balance. The length of the banana is zero. I don't >know if this is consistent with the rest of the problem as stated. >I didn't try to work it out. You must have read a different monkey problem than I read. No such assumption was stated. Furthermore, if this assumption were added, the problem would be self-contradictory. I stand by my answer of 5.75 inches. -- Dave Seaman {decvax|harpo|ihnp4|inuxc|seismo|ucbvax}!pur-ee!pucc-h!ags