Uniform Circular Motion (Kaplan)

[Young Chi]

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Question asks: "What is the minimum radius that a cyclist can ride around at 10 km/hr without slipping if the coefficient of friction between her tires and the road is 0.5?"

I converted km/hr to m/s, and understood "without slipping" to mean that the force of friction and centripetal force are equal. Apparently theres something I'm missing.

 

[DrknoSDN]

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[newsharpie]

3.84 meters. What answer did you find, and what is the correct answer you're not able to resolve?

How did you get 3.84m?

I put (mv^2)/r = (us)mg
us=coefficient of friction and 10km/h = 2.78m/s

solving for r, I got 1.54m. Did i do something wrong?

 

[DrknoSDN]

How did you get 3.84m?

I put (mv^2)/r = (us)mg
us=coefficient of friction and 10km/h = 2.78m/s

solving for r, I got 1.54m. Did i do something wrong?

No you are right. When I actually write it down it looks like 1.57 with g=9.8
Answer says 1.6 so you are probably right on.

 

[DrknoSDN]

Answer provided by Kaplan is here:
http://books.google.com/books?id=df...w&ved=0CDYQ6AEwAg#v=snippet&q=cyclist&f=false

Answer in another thread is here:
http://forums.studentdoctor.net/threads/physics-question-circular-motion.848591/