Kinematics Question 556
Question: A coin, placed on a rotating turn-table slips, when it’s placed at a distance of 9 cm from the centre.If the angular velocity of the turn-table it’s trippled, it will just slip, if it’s distance from the centre it’s [CPMT 2001]
Options:
A) 27 cm
B)9 cm
C) 3 cm
D) 1 cm
Show Answer
Answer:
Correct Answer: D
Solution:
In the given condition friction provides the required centripetal force and that it’s constant. i.e. mw2r=constant therefore $ r\propto \frac{1}{{{\omega }^{2}}} $ $ r _{2}=r _{1}{{( \frac{{\omega _{1}}}{{\omega _{2}}} )}^{2}}=9{{( \frac{1}{3} )}^{2}}=1cm $
