Home
Class 11
PHYSICS
A circular disc is rotating about its ow...

A circular disc is rotating about its own axis at a uniform angular velocity `omega`. The disc is subjected to uniform angular retardation by which its angular velocity is decreased to `omega/2` during `120` rotations. The number of rotations further made by it before coming to rest is

A

`120`

B

`60`

C

`40`

D

`20`

Text Solution

Verified by Experts

The correct Answer is:
C
`alpha` is constant `alpha=(omega_(1)^(2)-omega_(2)^(2))/(2 theta) , theta_(2)=(theta_(1))/3`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • SYSTEM OF PARTICLES

    NARAYNA|Exercise Level -II(H.W)|47 Videos

  • SYSTEM OF PARTICLES

    NARAYNA|Exercise Level-V|72 Videos

  • SYSTEM OF PARTICLES

    NARAYNA|Exercise NCERT based questions|15 Videos

  • PHYSICAL WORLD

    NARAYNA|Exercise C.U.Q|10 Videos

  • SYSTEM OF PARTICLES AND ROTATIONAL MOTION

    NARAYNA|Exercise EXERCISE - IV|39 Videos

Similar Questions

Explore conceptually related problems

A fly wheel is rotating about its own axis at an angular velocity 11 rad s^(-1) , its angular velocity in revolation per minute is

A rigid body rotating about a fixed axis with uniform angular retardation completes 33 rotations before its angular velocity is reduced to half of its initial value.Find the number of rotations made by the body further before it comes to rest.

Knowledge Check

  • A circular disc is rotating about its own axis, the direction of its angular momentum is

    A
    radial
    B
    along axis of rotation
    C
    along tangent
    D
    perpendicular to the direction of angular velocity

  • A ceiling fan is rotating about its own axis with uniform angular velocity omega . The electric current is switched off then due to constant opposing torque is its angular velocity is reduced to (2 omega)/3 as it completes 30 rotations. The number of rotations further it makes before coming to rest is

    A
    `18`
    B
    `12`
    C
    `9`
    D
    `24`

  • A cylinder full of water is rotating about its own axis with uniform angular velocity omega . Then the shape of free surface of water will be

    A
    parabola
    B
    elliptical
    C
    circular
    D
    spherical

    • Similar Questions

    Explore conceptually related problems

    A circular of radius 20 cm is rotating about its own axis at an angular velocity omega . The angular velocity of a particle 'A' which is at a distance 10 cm from the axis of rotation is

    A circular disc is rotating about its own axis at uniform rate completes 30 rotations in one minute.The angular velocity of disc in rad s^(-1) is

    A circular disc is rotating about its own axis at constant angular acceleration. If its angular velocity increases from 210 rpm to 420 rpm during 21 rotations then the angular acceleration of disc is

    A disc is rotating with angular velocity omega . If a child sits on it, what is conserved?

    A circular disc of radius R is rotating about its axis O with a uniform angular velocity omega"rad s"^(-1) as shown in the figure. The magnitude of the relative velocity of point A relative to point B on the disc is

    Home
    Profile