tag:blogger.com,1999:blog-5088860151651047897.post4835980411541817216..comments2024-03-25T10:56:59.380-04:00Comments on Jacobs Physics: How thick is a door, anyway?Greg Jacobshttp://www.blogger.com/profile/03854009948036330746noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-5088860151651047897.post-45626896898619478062011-05-09T14:05:33.023-04:002011-05-09T14:05:33.023-04:00The point is to pick the only one that is in any w...The point is to pick the only one that is in any way reasonable, not to be picky about the precise width of most doors we go through each day. I *have*, though rarely, seen 20 cm thick doors -- think a walk-in freezer, or even the door to our outdoor shed. I have never, and will never, see a 2 mm thin door, nor a 2 m or 20 m door. And that's the point... 20 cm is far, far more reasonable than the other answers. That's number sense.<br /><br />If you're uncomfortable, cut all the answers in half. The problem would work just as well.<br /><br />GCJGreg Jacobshttps://www.blogger.com/profile/03854009948036330746noreply@blogger.comtag:blogger.com,1999:blog-5088860151651047897.post-3439135159786588512011-05-09T13:38:30.660-04:002011-05-09T13:38:30.660-04:00In your example question, there is hardly a reason...In your example question, there is hardly a reasonable answer. If the answer is supposed to be A, then 20cm is a pretty ridiculously fat door. I've never in my life seen a door 20cm thick. That's almost 8 inches thick, or two thirds of a foot! If the answer is supposed to be B, that is a super thin door at only 2mm. That's thinner than a piece of cardboard and about as thick as a textbook cover! I understand that you're trying to get them to get an instinct for the meaning of numbers, but you gotta be more reasonable than this man. Maybe you should brush up on your number meanings a little bit.Anonymousnoreply@blogger.com