A coin, placed on a rotating turntable slips, when it is placed at a distance of `9cm` from the center. If the angular velocity of the turnable is tripled, it will just slip, If its distance from the center is

Options

A. 27 cm
B. 9 cm
C. 3 cm
D. 1 cm

Answer

D

Explanation

Necessary centripetal force to the coin is provided by friction. Thus, `mromega_(max)^(2)=mumg" or "r=(mug)/(omega_(max)^(2))`
`omega_(max)` is made three times. Therefore, distance from centre r will remain `(1)/(9)` times that is 1 cm.