A cyclist has to lean inwards when negotiating a curved unbanked road. The cyclist leans with an angle $\theta$ to the vertical. $N$ is the normal reaction given by $N=mg$, where $m$ is the mass of the cyclist and the bicycle combined. The radius of the curved road is $R$. The force of friction is given by $F=\mu N$ where $\mu$ is the co-efficient of friction. Assuming the cyclist skids which of the following is true?

Question

$v \gt \sqrt {\mu g R}, \quad v \lt \sqrt {\mu g R},\quad$$v = \sqrt {\mu m g R},$$\quad v \gt \sqrt {\mu m g R}$