Calculating Coefficient of Friction for a Coin on a Turntable

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The discussion revolves around calculating the coefficient of static friction for a coin on a turntable, where the user suspects a typo in the textbook answer due to an extra zero. The user calculated the coefficient as 0.0085, while the book states ".085 0," leading to confusion about the correct value. A participant pointed out that the user may have incorrectly converted units from centimeters to meters, which contributed to the discrepancy. The user acknowledged this mistake, attributing it to a habit formed from previous coursework. Overall, the conversation highlights the importance of accurate unit conversion in physics calculations.
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I've got the answer to the problem but I'm one decimal place off from the back of the book and am suspecting a typo (no, lol... not that presumptuous...) the reason for the suspicion is that there's a zero after the answer where the units would go but this question is asking for a coefficient of friction so, of course, there should be no units... I'm just wondering if that zero was somehow misplaced in printing/formatting... I could be completely missing something though.

Homework Statement


A coin placed 30.0cm from the center of a rotating, horizontal turntable slips when its speed is 50.0cm/s. What is the coefficient of static friction between the coin and turntable?


Homework Equations


\mu_{s}=\frac{v^{2}}{gr}

\mu_{s}=\frac{.05m/s^{2}}{(9.81m/s^{2})*.03m/s^{2}}

\mu_{s}=.0085


The Attempt at a Solution



The book states ".085 0"

Is my solution correct or am I missing something?

Thanks!
 
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atmega-ist said:
I've got the answer to the problem but I'm one decimal place off from the back of the book and am suspecting a typo (no, lol... not that presumptuous...) the reason for the suspicion is that there's a zero after the answer where the units would go but this question is asking for a coefficient of friction so, of course, there should be no units... I'm just wondering if that zero was somehow misplaced in printing/formatting... I could be completely missing something though.

Homework Statement


A coin placed 30.0cm from the center of a rotating, horizontal turntable slips when its speed is 50.0cm/s. What is the coefficient of static friction between the coin and turntable?


Homework Equations


\mu_{s}=\frac{v^{2}}{gr}

\mu_{s}=\frac{.05m/s^{2}}{(9.81m/s^{2})*.03m/s^{2}}

\mu_{s}=.0085


The Attempt at a Solution



The book states ".085 0"

Is my solution correct or am I missing something?

Thanks!

You didn't convert from cm to meters correctly. The units aren't written properly, either. Is that just a typing error on your part?
 
You didn't convert from cm to meters correctly.

I have no words...

You're exactly right. Two semesters of chemistry with EVERYTHING in mm and mL started a pretty bad habit of glossing over conversions.

The units aren't written properly, either. Is that just a typing error on your part?

Sure is. I think I got a bit carried away with the ol' CTRL+V.

Thanks so much for the second look (a.k.a. "smack-in-the-back-of-the-head").

Lol... Apologies for taking up server space for this one :rolleyes:
 
Don't worry, I think we've all been there! :wink:
 
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