Laws Of Motion Question 14
Question 14 - 2024 (31 Jan Shift 1)
A coin is placed on a disc. The coefficient of friction between the coin and the disc is $\mu$. If the distance of the coin from the center of the disc is $r$, the maximum angular velocity which can be given to the disc, so that the coin does not slip away, is :
(1) $\frac{\mu g}{r}$
(2) $\sqrt{\frac{r}{\mu g}}$
(3) $\sqrt{\frac{\mu g}{r}}$
(4) $\frac{\mu}{\sqrt{rg}}$
Show Answer
Answer: (3)
Solution:
$N=mg$
$f=m \omega^{2} r$
$f=\mu N$
$\mu mg=mr \omega^{2}$
$\omega=\sqrt{\frac{\mu g}{r}}$
