Rotational Motion Question 7
Question 7 - 29 January - Shift 1
A car is moving on a horizontal curved road with radius $50 m$. The approximate maximum speed of car will be, if friction between tyres and road is 0.34. [Take $g=10 ms^{-2}$ ]
(1) $3.4 ms^{-1}$
(2) $22.4 ms^{-1}$
(3) $13 ms^{-1}$
(4) $17 ms^{-1}$
Show Answer
Answer: (3)
Solution:
Formula: Friction force
$ f_s=\frac{mv^{2}}{r} $
For maximum speed in safe turning,
$f_s=f_s \max =\mu mg$
$v _{\max }($ for safe turning $=\sqrt{\mu rg}$
$=\sqrt{0.34 \times 50 \times 10} \approx 13 m / s$
