Question

A coin placed on a rotating table just slips if it is placed at a distance 4r from the centre. On doubling the angular velocity of the table, the coin will just slip when at a distance from the centre equal to :

• A. 4r
• B. 2r
• C. r
• D. r/4

Answer 1

Answer: (C)

r

Answer 2

\ w = $\sqrt{\frac{µg}{r}}$

w a $\frac{1}{\sqrt{r}}$ Ž r a $\frac{1}{\omega^{2}}$

since w is double thus

r' = $\frac{4r}{4}$ = r