Level Road & Rotating Platform
A 0.5 kg mass is in contact against the inner wall of a cylindrical drum of radius 4 m rotating about its vertical axis. The minimum rotational speed of the drum to enable the mass to remain stuck to the wall (without falling) is 5 rad/s. The coefficient of friction between the drum’s inner wall surface and mass is _________. (Take )
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Answer: (a)
- Wall's normal force gives the centripetal force: .
- Friction holds the weight: .
- So the answer is (a) 0.1.