Question

A gramophone disc performs 60 rev/min if the coefficient if friction between the coin and disc is 0.4. Find the maximum distance from the centere of the disc at which the coin can be kept without slipping (g=10 m/$s^2$)

• A. 4 cm
• B. 10.15 m
• C. 2 cm
• D. 2 m

Answer 1

The correct option is A 4 cm

From fig.

$F=\frac{m{v}^2}{R}\mu mg=\frac{m{v}^2}{R}\frac{4}{10}\times 10=R\times 1\times 1\Rightarrow R=4$