These fields are all optional and need only
be supplied if you would like a direct reply.
Subject
Your email address
Your real name
You must answer this!
If you don't, my spam filtering will
ensure that I never see your email.
What's 8 plus five (in digits only)?
Please make your changes here and then
Editing tips and layout rules.
File: WeighingTheOptions A ChallengeQuestion ... !! WeighingTheOptions [[[< images/ScalePicture.gif ]]] Consider a good, old-fashioned spring-balance. The more you hang from it, the larger the reading. Suppose it's been calibrated, and when you hang one kilogram from it the dial reads 1kg. [[[> images/ScaleQuestion.gif ]]] Now look at the arrangement we have here on the right. We have two frictionless pulleys and a light, inextensible string such as is only ever found in a physics textbook. We put the (effectively massless) spring balance in the middle, and we hang a kilogram from each end of the string. What reading do we get?