A boy is sitting on the horizontal platform of a joy wheel at a distance of $5 \,m$ from the center. The wheel begins to rotate and when the angular speed exceeds $1 \,rad / s$, the boy just slips. The coefficient of friction between the boy and the wheel is $\left(g=10 \,m / s ^2\right)$
A$0.5$
B$0.32$
C$0.71$
D$0.2$
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A$0.5$
a (a)
$\frac{v^2}{r}=\omega^2 r=\mu g$
$m=0.5$
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