Question

If a cyclist moving with a speed of $4.9\, m / s$ on a level road can take a sharp circular turn of radius $4 \,m$, then coefficient of friction between the cycle tyres and road is

• A. 0.51
• B. 0.41
• C. 0.71
• D. 0.61

Answer 1

Answer: (D)

0.61

Answer 2

We know that while a cyclist moving with a speed $v$ takes a sharp turn on a circular track of radius $r$, the coefficient of friction is given by $\mu=\tan \,\theta=\frac{v^{2}}{r g}$ Here $v=4.9\, m / s$ $r=4 \,m$ and $g=9.8\, m / s ^{2}$ $\therefore \,\,\,\,\,\mu=\frac{4.9 \times 4.9}{4 \times 9.8}=0.61$