Home
Class 11
PHYSICS
A man places a chain (of mass m and leng...

A man places a chain (of mass `m` and length `l`) on a table slowly. Initially, the lower end of the chain just touches the table. The main brings down the chain by length `l//2`. Work done by the man in this process is

A

`-mgl/2`

B

`-(mgl)/4`

C

`-(3mgl)/8`

D

`-(mgl)/8`

Text Solution

Verified by Experts

The correct Answer is:
C
The work done by man is negative of magnitude of decreases in potential energy of chain

`DeltaU=mgL/2-m/2 g L/4=3mgL/8 :. W=-(3mg l)/8`
Promotional Banner

Topper's Solved these Questions

Similar Questions

Explore conceptually related problems

A chain of mass m and length l is placed on a table with one-sixth of it hanging freely from the table edge. The amount of work. done to pull the chain on the table is

Avertical, uniform chain of total mass M and length L is being lowered onto atable at aconstant speed V. At time t=0 the lower end of the chain toucjhes the table. Find the exerted by the chain on the table as a function of time, as the chain is deposited on the table.

A unifrom chain of mass M and length L lies on a table with nth part of it hanging off the table. Find the work required to slowly pull the hanging part up to the table.

A uniform chain of mass m and length l overhangs a table with its two third part on the table. Fine the work to be done by a person to put the hanging part back on the table.

A uniform chain of mass m and length l is lying on a horizontal table with one-third of its length hanging over the edge of the table. What is the speed of the chain, when it just loses contact with the table?

A uniform chain of mass m and length l is kept on a horizontal table with half of its length hanging from the edge of the table.Work done in pulling the chain on to the table so that only 1/5 th of its length now hangs from the edge is K((mgl)/(200)) .Find the value of K.

A chain of mass m and length l lies on a horizontal table. The chain is allowed to slide down gently from the side of the table. Find the speed of the chain at the instant when last link of the chain slides from the table. Neglect friction everywhere. (a) the force from thelicopter and (b) the gravitational force on her (c ) What are speed ot the kinetic energy and. (d) the speed of the astronaut just before she reaches the helicopter?

A uniform chain of mass m & length L is kept on a smooth horizontal table such that (L)/(n) portion of the chaing hangs from the table. The work dione required to slowly bringsthe chain completely on the table is

RESONANCE-WORK POWER AND ENERGY-Exercise
  1. A block attached to a spring, pulled by a constant horizontal force, i...

    Text Solution

    |

  2. A body is projected with kinetic energy k at angle phi with the vertic...

    Text Solution

    |

  3. A man places a chain (of mass m and length l) on a table slowly. Initi...

    Text Solution

    |

  4. Power supplied to a mass 2 kg varies with time as P = (3t^(2))/(2) wat...

    Text Solution

    |

  5. A constant power P is applied to a particle of mass m. The distance tr...

    Text Solution

    |

  6. A rigid body is acted upon by a horizontal force which is inversely pr...

    Text Solution

    |

  7. The graph between the resistive force F acting on a body and the dista...

    Text Solution

    |

  8. A particle move in a straight line with retardation proportional to it...

    Text Solution

    |

  9. A body is falling under gravity . When it loses a gravitational potent...

    Text Solution

    |

  10. A block of mass m is attached to two unstretched springs of spring con...

    Text Solution

    |

  11. A body of mass m dropped from a certain height strikes a light vertica...

    Text Solution

    |

  12. A particle moves with a velocity v=(5hati-3hatj + 6hatk) ms^(-1) under...

    Text Solution

    |

  13. An electric motor creates a tension of 4500 newton in a hoisting cable...

    Text Solution

    |

  14. The potential energy of a partical veries with distance x as shown in ...

    Text Solution

    |

  15. The potential energy of a force filed vec(F) is given by U(x,y)=sin(x+...

    Text Solution

    |

  16. A spring of force constant 800N//m has an extension of 5cm. The work d...

    Text Solution

    |

  17. A body is moved along a straight line by a machine delivering constant...

    Text Solution

    |

  18. The total work done on a particle is equal to the change in its mechan...

    Text Solution

    |

  19. A ring of mass m can slide over a smooth vertical rod. The ring is con...

    Text Solution

    |

  20. The kinetic energy of a particle continuously icreses with time

    Text Solution

    |