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# Friction and Circular Motion watch

1. shouldn't it be:
v=( meu*R*g)^(1/2)
so then when rearranged,
meu= v^2/Rg
2. μ is mu.

F = μR

F = (mv^2)/r = μR --> μ = (mv^2)/(rR)

R = mg, so μ = (mv^2)/(rmg) = (v^2)/(rg) = answer (1).

Edit: I used r as radius and R as the reaction force. We need more letters.
3. (Original post by ombtom)
μ is mu.

F = μR

F = (mv^2)/r = μR --> μ = (mv^2)/(rR)

R = mg, so μ = (mv^2)/(rmg) = (v^2)/(rg) = answer (1).

Edit: I used r as radius and R as the reaction force. We need more letters.
Oh, okay thanks. Then the book's answer is probably wrong.
4. (Original post by 123PC)
Oh, okay thanks. Then the book's answer is probably wrong.
What does the book say? I do make a lot of mistakes.

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