Home
Class 11
PHYSICS
the door of an almirah is 6 ft high, 1.5...

the door of an almirah is 6 ft high, 1.5 ft wide and weights 8 kg. The door is supported by two hinges situated at a distance of 1 ft from the ends. If the magnitude of the forces exerted by the hinges on the door are equal find this magnitude.

Text Solution

Verified by Experts

The correct Answer is:
C, D

According the question
`8g=F_1+F_2`
=N_1=N_2`
Since `R_1=R_2`
Therefore `F_1=F_2`
`rarr 2F_1=8g`
`rarr F_1=40`
Let us take torque about the point B we will get
`N_1xx4=8gx0.75` ltbr `rarr N_1=((50x3))/((4xx4))=15N`
Therefore `sqrt(F_1^2+N_1^2)=R_1`
`=sqrt(40^2+15^2)`
`=42.72=43N`
Promotional Banner

Topper's Solved these Questions

  • ROTATIONAL MECHANICS

    HC VERMA|Exercise Objective -2|15 Videos
  • REST AND MOTION : KINEMATICS

    HC VERMA|Exercise Exercises|51 Videos
  • SIMPLE HARMONIC MOTION

    HC VERMA|Exercise Exercises|58 Videos

Similar Questions

Explore conceptually related problems

Two long and parallel street wires carrying current of 2A and 5A in the opposite direction are separated by a distance of 1 cm. Find the nature and magnitude of the magnetic force between them.

Shows a convex lens of focal length 12 cm lying in a uniform magnetic field B of magnitude 1.2 T parallel to its principal axis. A particle having a charge 2.0X 10^(-3) C and mass 2.0 X 10^(-5) kg is projected perpendiucular to the plane of the diagram with a speed of 4.8 ms ^(-1). The particle moves along a circle with its centre on the principal axis at a distance of 18 cm from the lens. Show that the image of the particle goes along a circle end find the radius of thet circle.

An arch is in the from of a semi - ellipse. It is 8 m wide and 2 m high at the centre. Find the height of the arch at a point 1.5 m from one end.

A uniform magnetic field of 1.5 T exists in a cylindrical region of radius 10.0 cm, its direction parallel to the axis is along east to west. A wire carrying current of 7.0 A in the north to south direction passes through this region. What is the magnitude and direction of the force on the wire if, a. the wire intersects the axis, the wire is turned from N S to north east-south west direction. c. the wire in the N-S direction is lowered from the axis by a distance 6.0 cm.

A dumb bell consists of two identicasl small balls offmss 1/2 kg each connected to the ends of a 50 cm long light rod. The dumb bell is rotating about a fixed axis through the centre of the rod and perpendicular to it t an angular speed of 10 rad/s. An impulsive force of average magnitude 5.0 N acts on one of the masses in the direction of its velocity for 0.10s. Find the new angular velocity of the system.

A long, straight wire carrying a current of 1.0 A is placed horizontally in a uniform magnetic field B= ( 1.0 xx 10^-5) T pointing vertically upward. Find the magnitude of the resultant magnetic field at the points P and Q, both situated at a distance of 2.0 cm from the wire in the same horizontal plane.

HC VERMA-ROTATIONAL MECHANICS-Exercises
  1. Suppose the friction coefficient between the ground and the ladder of ...

    Text Solution

    |

  2. A 6.5 m long ladder rests against as vertical wall reaching a height o...

    Text Solution

    |

  3. the door of an almirah is 6 ft high, 1.5 ft wide and weights 8 kg. The...

    Text Solution

    |

  4. A uniform rod of length L rests against a smooth roller as shown in fi...

    Text Solution

    |

  5. A uniform rod of mass 300 g and length 50 cm rotates at a uniform angu...

    Text Solution

    |

  6. A uniform square plate of mass 2.0 kg and edge 10 cm rotates about one...

    Text Solution

    |

  7. Calculate the ratio of the angular momentum of the earth about its axi...

    Text Solution

    |

  8. Two particles of masses m1 and m2 are joined by a light rigid rod of l...

    Text Solution

    |

  9. A dumb bell consists of two identicasl small balls offmss 1/2 kg each ...

    Text Solution

    |

  10. A wheel of moment of inertia 0.500 kg-m^2 and radius 20.0 cm is rotati...

    Text Solution

    |

  11. A diver having a moment of inertia of 6.0 kg-m^2 about an axis through...

    Text Solution

    |

  12. A boy is seated in a revolving chair revolving at an angular speed of ...

    Text Solution

    |

  13. A boy is standing on a platform which is free to rotate about its axis...

    Text Solution

    |

  14. A wheel of moment of inertia 0.10 kg-m^2 is rotating about a shaft at ...

    Text Solution

    |

  15. A kid of mass M stands at the edge of a platform of radius R which can...

    Text Solution

    |

  16. Suppose the platform of the previous problem is brought to rest with t...

    Text Solution

    |

  17. Suppose the platform with the kid in the previous problem is rotting i...

    Text Solution

    |

  18. A uniform rod of mass m and length l is struck at an end by a force F ...

    Text Solution

    |

  19. A uniform rod of length L lies on a smooth horizontal table. A particl...

    Text Solution

    |

  20. Suppose the particle of the previous problem has a mass m and a speed ...

    Text Solution

    |