perplexus.info :: Calculus : What's wrong with CDs?

What's wrong with CDs? (Posted on 2005-03-30)

The diameter of a long playing vinyl record is 12 inches. The unused center has a diameter of 4 inches, and there is a smooth outer edge that is 1 inch wide. If there are 91 grooves to the inch, how far does the needle travel within the groove during playback of the record?

Submitted by Erik O.

Rating: 4.0000 (1 votes)

Solution: (Hide)

Charlie and CeeAnne provide two ways of coming to the result of approximately 6003.6 inches here and here.

Comments: ( You must be logged in to post comments.)

Subject	Author	Date
Puzzle Answer	K Sengupta	2022-07-23 01:01:21
THE CORRECT SOLUTION!	kris	2005-04-04 16:45:49
Two similarities	TomM	2005-04-02 00:40:09
re: Simpler Solution	Charlie	2005-03-31 19:38:11
Simpler Solution	CeeAnne	2005-03-31 19:26:45
re(2): Solution	Dustin	2005-03-31 01:04:26
re: Solution	asdfjfaadslkfj	2005-03-30 23:27:58
An Aside--trivia	Charlie	2005-03-30 15:53:06
re: Solution	Charlie	2005-03-30 15:25:19
Solution	e.g.	2005-03-30 14:43:32
Non-Calculus Approximation--spoiler	Charlie	2005-03-30 14:14:46

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