Question
Question: A rod of mass m and length fits into a hollow tube of same length and mass. The tube is rotated with...
A rod of mass m and length fits into a hollow tube of same length and mass. The tube is rotated with an initial angular velocity ω0 and the rod slips through the rough hollow surface. The angular velocity of the rod as it slips out of the tube is
A
2ω0
B
4ω0
C
16ω0
D
7ω0
Answer
4ω0
Explanation
Solution
There is no external torque acting on the system. Hence angular momentum remains conserved.
I1ω1 = I2ω2
I1 = 2M2/3; I2 = [2M(2)2/3] ⇒ ω2 = ωo/4