Monday, January 8, 2007
Physics problem: Poof and Foop
One of my favorite puzzle books is Thinking Physics, written and illustrated by Lewis C. Epstein. The dozens of challenging multiple-choice puzzles have lucid explanations that help you gain an intuitive feel for physics that make you a better puzzle solver. There's not a lot of math in the book -- instead, you have to construct a mental physics lab and run the experiments in your head (hence the title of the book).
One of my favorites is called "Poof and Foop."
Submit your answer and reasoning here: LinkThis is a stumper. If a can of compressed air is punctured and the escaping air blows to the right, the can will move to the left in a rocket-like fashion. Now consider a vacuum can that is punctured. The air blows to the left as it enters the can. After the vacuum is filled the can will
a) be moving to the left
b) be moving to the right
c) not be moving
posted by Mark Frauenfelder at 01:51:32 PM permalink | Other blogs' comments




This is a stumper. If a can of compressed air is punctured and the escaping air blows to the right, the can will move to the left in a rocket-like fashion. Now consider a vacuum can that is punctured. The air blows to the left as it enters the can. After the vacuum is filled the can will








