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The below is the sixth question of the very first chapter from halliday and resnicks fundamentals of physics text,which i'am not able to comprehend.

Harward Bridge,which connects MIT with its fraternities accross the Charles River,has a length of 364.4 Smoots plus one ear.The unit of one Smoot is based on the length of Oliver Reed Smoot,Jr.,class of 1982,who was carried or dragged length by length across the bridge so that other pledge members of the Lambda Chi Alpha fraternity could mark off (with paint) 1-Smoot lengths along the bridge.The marks have been repainted biannually by fraternity pledges since the initial measurement,usually during times of traffic congestion so that the police cannot easily interfere.(Presumably,the police were originally upset because the Smoot is not an SI unit,but these days they seem to have accepted the unit.) the below figure shows three prallel paths,measured in Smoots (S),Willies (W),and Zeldas (Z).What is the length of 50.0 Smoots in (a) Willies and (b) Zeldas?

enter image description here

The method used in this text to solve these kind of problems is chain link conversion where in you set up the problem in such a way the unwanted units cancel.I would be glad if someone could help me in setting it up so that i can work through it.

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marked as duplicate by David Z Mar 19 '12 at 15:29

This question was marked as an exact duplicate of an existing question.

That "possible duplicate" is of no help to me,so please reopen this for me and let others answer. – alok Mar 19 '12 at 15:34
I agree, though note that for homework questions we only give conceptipual hints, not the full solution. – Manishearth Mar 19 '12 at 15:38
A couple of things: if I hadn't closed it as an exact duplicate, I would have closed it as too localized because this is one of those "do-my-homework" questions we don't allow; also, the procedure you need to solve this question is described in the (formerly) linked duplicate's answers. If you edit the question to focus on the concept that is giving you trouble and also show how you used the answers of the linked question and were still unable to solve it, then I'll be happy to consider reopening it. – David Z Mar 19 '12 at 17:34

The catch here is that there's no zero mark for Zeldas.

It should be pretty easy to calculate the conversion factor between S and W; since the length of the bridge should stay the same.

For S and Z, note that we can't assume Z to start at 0 along with S and W. So, equate the distances covered in going from the 32/60 mark to the end of the bridge. You'll get another conversion factor. Now use the conversion factors using the chain-link-conversion method.

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