Home
Class 11
PHYSICS
A ring of radius R is first rotated with...

A ring of radius R is first rotated with an angular velocity `omega_(0)` and then carefully placed on a rough horizontal surface. The cofficent of fgriction between the surface and the ring is `mu`. Time after which its angular speed is reduced to half is

A

`(omega_(0)muR)/(2g)`

B

`(omega_(0)g)/(2muR)`

C

`(2omega_(0)R)/(mug)`

D

`(omega_(0)R)/(2mug)`

Text Solution

Verified by Experts

The correct Answer is:
D
Taking `tau` about CM

`mumgR=MR^(2) alpha`
`mug=Ralpha`
`alpha=(mug)/R`
`omega=omega_(0)=(mug)/Rf=(omega_(0))/2`
`(omega_(0))/2=(mug)/Rfimpliesf=(omega_(0)R)/(2mug)`
Promotional Banner

Topper's Solved these Questions

  • RIGID BODY DYNAMICS 2

    CENGAGE PHYSICS ENGLISH|Exercise Multiple Correct|26 Videos

  • RIGID BODY DYNAMICS 2

    CENGAGE PHYSICS ENGLISH|Exercise Linked Comprehension|71 Videos

  • RIGID BODY DYNAMICS 2

    CENGAGE PHYSICS ENGLISH|Exercise Subjective|19 Videos

  • RIGID BODY DYNAMICS 1

    CENGAGE PHYSICS ENGLISH|Exercise Integer|11 Videos

  • SOUND WAVES AND DOPPLER EFFECT

    CENGAGE PHYSICS ENGLISH|Exercise Integer|16 Videos

Similar Questions

Explore conceptually related problems

A ring of radius R is first rotated with an angular velocity omega and then carefully placed on a rough horizontal surface. The coefficient of friction between the surface and the ring is mu . Time after which its angular speed is reduced to half is

A ring of radius R is rotating with an angular speed omega_0 about a horizontal axis. It is placed on a rough horizontal table. The coefficient of kinetic friction is mu_k . The time after it starts rolling is.

A uniform disc of radius R is spinned to the angular velocity omega and then carefully placed on a horizontal surface. How long will the disc be rotating on the surface if the friction coeffiecient is equal to k ? The pressure exerted by the disc on the surface can be regarded as uniform.

A disc is given an initial angular velocity omega_(0) and placed on a rough horizontal surface as shown Fig. The quantities which will not depend on the coefficient of friction is/are

A uniform disc of mass m and radius R is rotated about an axis passing through its center and perpendicular to its plane with an angular velocity omega_() . It is placed on a rough horizontal plane with the axis of the disc keeping vertical. Coefficient of friction between the disc and the surface is mu , find (a). The time when disc stops rotating (b). The angle rotated by the disc before stopping.

A disc of mass m and radius R rotating with angular speed omega_(0) is placed on a rough surface (co-officient of friction =mu ). Then

A hoop of radius r mass m rotating with an angular velocity omega_(0) is placed on a rough horizontal surface. The initial velocity of the centre of the hoop is zero. What will be the velocity of the centre of the hoop when it cases to slip ?

A ring of radius 'r' and mass per unit length 'm' rotates with an angular velocity 'omega' in free space then tension will be :

A conducting ring of radius r having charge q is rotating with angular velocity omega about its axes. Find the magnetic field at the centre of the ring.

A conducting ring of radius r having charge q is rotating with angular velocity omega about its axes. Find the magnetic field at the centre of the ring.

CENGAGE PHYSICS ENGLISH-RIGID BODY DYNAMICS 2-Single Correct
  1. A solid sphere rests on a horizontal surface. A horizontal impulse is ...

    Text Solution

    |

  2. In Fig a sphere of radius 2 m rolls on a plank. The accelerations of t...

    Text Solution

    |

  3. A ring of radius R is first rotated with an angular velocity omega(0) ...

    Text Solution

    |

  4. Two bodies with moment of inertia I1 and I2 (I1 gt I2) have equal angu...

    Text Solution

    |

  5. In Fig. the velocities are in ground frame and the cylinder is perform...

    Text Solution

    |

  6. A sphere has to purely roll upwards. At an instant when the velocity o...

    Text Solution

    |

  7. A string is wrapped around a cylinder of mass M and radius R. The stri...

    Text Solution

    |

  8. A smooth uniform rod of length L and mass M has two identical beads of...

    Text Solution

    |

  9. A uniform thin rod of length l and mass m is hinged at a distance l//4...

    Text Solution

    |

  10. A disc is rotated about its axis with a certain angular velocity and l...

    Text Solution

    |

  11. A uniform circular disc of mass M and radius R rolls without slipping ...

    Text Solution

    |

  12. A child is standing with folded hands at the center of a platform rota...

    Text Solution

    |

  13. A yo-yo is placed on a rough horizontal surface and a constant force F...

    Text Solution

    |

  14. A ring, cylinder and solid sphere are placed on the top of a rough inc...

    Text Solution

    |

  15. If a spherical ball rolls on a table without slipping, the fraction of...

    Text Solution

    |

  16. A disc of mass m and radius R moves in the x-y plane as shown in Fig. ...

    Text Solution

    |

  17. A spool is pulled horizontally on rough surface by two equal and oppos...

    Text Solution

    |

  18. A disc of mass m and radius R moves in the x-y plane as shown in Fig. ...

    Text Solution

    |

  19. An impulse J = mv at one end of a stationary uniform frictionless rod ...

    Text Solution

    |

  20. A solid sphere of mass m is lying at rest on a rough horizontal surfac...

    Text Solution

    |