Home
Class 11
PHYSICS
vecF = a hat i + 3hat j+ 6 hat k and vec...

`vecF = a hat i + 3hat j+ 6 hat k` and `vec r = 2hat i-6hat j -12 hat k`. The value of `a` for which the angular momentum is conserved is

A

`-1`

B

`0`

C

`1`

D

`2`

Text Solution

Verified by Experts

The correct Answer is:
A
`vec(tau)=vec(r)xxvec(F)` and `tau=(dL)/(dt)=0`
Promotional Banner

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 force vec F = prop hat i + 3 hat j + 6 hat k is acting at a point vec r = 2 hat i - 6 hat j - 12 hat k . The value of prop for which angular momentum about origin is conserved is.

Vectors vec A=hat i+hat j-2hat k and vec B=3hat i+3hat j-6hat k are

The position of a particle is given by vec r = hat i + 2hat j - hat k and its momentum is vec p = 3 hat i + 4 hat j - 2 hat k . The angular momentum is perpendicular to

Let vec a=2 hat i- hat j+ hat k , vec b= hat i+2 hat j= hat ka n d vec c= hat i+ hat j-2 hat k be three vectors. A vector in the plane of vec ba n d vec c , whose projection on vec a is of magnitude sqrt(2//3) , is a. 2 hat i+3 hat j-3 hat k b. 2 hat i-3 hat j+3 hat k c. -2 hat i- hat j+5 hat k d. 2 hat i+ hat j+5 hat k

The projection of hat i+3hat j+hat k on 2hat i-3hat j+6hat k is :

underset with a = 2hat i + hat j-3hat k, vec b = -hat i + hat j + 2hat k, vec c = 4hat i + 3hat k

Let vec a= hat i+ hat j+ hat k , vec b= hat i- hat j+ hat ka n d vec c= hat i- hat j- hat k be three vectors. A vector vec v in the plane of vec aa n d vec b , whose projection on vec c is 1/(sqrt(3)) is given by a. hat i-3 hat j+3 hat k b. -3 hat i-3 hat j+3 hat k c. 3 hat i- hat j+3 hat k d. hat i+3 hat j-3 hat k

The lines vec r=(hat i+hat j+hat k)alpha+3hat k and vec r=(hat i-2hat j+hat k)beta+3hat k

vec r=(4hat i-hat j)+lambda(hat i+2hat j-3hat k) and vec r=(hat i-hat j+2hat k)+mu(2hat i+4hat j-5hat k)

NARAYNA-SYSTEM OF PARTICLES-Level -I(H.W)
  1. A child is standing with folded hands at the center of a platform rota...

    Text Solution

    |

  2. If radus of earth shrinks by 0.1% without change in its mass, the perc...

    Text Solution

    |

  3. A ballet dancer spins about a vertical axis at 60 rpm with his arms cl...

    Text Solution

    |

  4. A metallic circular wheel is rotating about its own axis without frict...

    Text Solution

    |

  5. A uniform circular disc of radius R is rotating about its own axis wit...

    Text Solution

    |

  6. A particle of mass m is moving in a plane along a circular path of rad...

    Text Solution

    |

  7. vecF = a hat i + 3hat j+ 6 hat k and vec r = 2hat i-6hat j -12 hat k. ...

    Text Solution

    |

  8. What will be the duration of the day, if the earth suddenly shrinks to...

    Text Solution

    |

  9. A mass is whirled in a circular path with an angular momentum L. If th...

    Text Solution

    |

  10. A disc rotates with angular velocity omega and kinetic energy E. Then ...

    Text Solution

    |

  11. A wheel at rest has M.I. 2/(pi^2) kgm^2. It is rotated by a 60W motor ...

    Text Solution

    |

  12. The shaft of a motor is making 1260rpm. The torque supplied by the mot...

    Text Solution

    |

  13. An electric motor rotates a wheel at a constant angular velocity 10rps...

    Text Solution

    |

  14. The work done in increasing the angular frequency of a circular ring o...

    Text Solution

    |

  15. A ring is allowed to roll down on an incline of 1 in 10 without slippi...

    Text Solution

    |

  16. A cylinder is released from rest from the top of an incline of inclina...

    Text Solution

    |

  17. For a body rolling along a level surface, without slipping the transla...

    Text Solution

    |

  18. A solid sphere and a spherical shell roll down an incline from rest fr...

    Text Solution

    |

  19. When a solid sphere is rolling along level surface the percentage of i...

    Text Solution

    |

  20. A thin ring of mass 1kg and radius 1m is rolling at a speed of 1ms^(-1...

    Text Solution

    |