Home
Class 11
PHYSICS
As mosquito is sitting on an L.P. record...

As mosquito is sitting on an L.P. record disc rotating on a turn table at `33 1/3` revolutions per minute. The distance of the mosquito from the center of the turn table is 10 cm. Show that the friction coefficient between the record and the mosquito is greater than `pi^2/81`. Take `g=10m/s^2`

Text Solution

Verified by Experts

The correct Answer is:
A

A mosquito is sitting on an L.P record disc and rotating on a turn table at `33 1/2` rpm.
`n=33/1/3 rpm`
`100(3xx60)rps`
`:. omega==2pixx100/180`
`=(10pi)/9 rad/sec`
`r=10cm=0.4m`
`g=10 m/sec^2`
`mumg?=mromega^2`
`:. mugt(romega^2)/g.=(0.1xx(10pi/9)^2)/10`
`rarr mugt(pi^2/81)`
Promotional Banner

Topper's Solved these Questions

  • CIRCULAR MOTION

    HC VERMA|Exercise Objective 2|7 Videos
  • CENTRE OF MASS, LINEAR MOMENTUM, COLLISION

    HC VERMA|Exercise Exercises|64 Videos
  • FLUID MECHANICS

    HC VERMA|Exercise Exercises|35 Videos

Similar Questions

Explore conceptually related problems

The fricition coefficient between the table and block shown in fig. is 0.2 find the acceleration of the system (Take g=10 m//s^(2) )

A coin just remains on a disc rotating at a steady rate of 180r.p.m .A coin is kept at a distance of 2 cm from the axis of rotationn . The coefficient of fricition between the coin and the disc is _____ [ gg= 9.8 m//s^(2)]

A disc rotates about its aixs of symmetry in a horizontal plane at a steady rate of 3.5 revolutions per second A coin placed at a distance fo 1.25 cm form the axis of ratation remains at rest on the disc The coefficient of friction between the coin and the disc is : (g=10//s^(2))

A boy is sitting on the horizontal platform of a joy wheel at a distance of 5 m from the center. The wheel begins to rotate and when angular speed exceeds 1 rad/s, the boy just slips. The coefficient of friction between the boy and the wheel is (g=10m//s^(2))

Find the maximum speed at which a car can take turn round a curve of 30 cm radius on a level road if the coefficient of friction between the tyres and the road is 0.4. Take g = 10 ms^(-2) .

A gramophone disc is set revolving in a horizontal plane at the rate of 33(1)/(2) revolutions per minute. It is found that a small coin placed on the disc will remain there if its centre is not more than 5 cm from the axis of rotation. Calculate the coefficient of friction between the coin and the disc [Hint : Centripetal force = m omega^(2)r= Frictional force = mu N=mu mg ]

A body is kept on a horizontal disc of radius 2 m at a distance of 1 m from the centre . The coefficient of friction between the body and the surface of disc is 0.4. The speed of rotation of the disc at which the body starts slipping is (g=10 m//s^2 )

Find the maximum speed at which a car can turn round a curve of 30 m radius on a level road if coefficient of friction between the tyress and road is 0.4. Take g = 10 m//s^(2) .

A small coin is placed on a flat horizontal turn table. The turn table is observed to make three revolutions in 3.14 sec . What is the coefficient of static friction between the coin and turn table if the coin is observed to slide off the turn table when it is greater than 10cm from the centre of turn table .

HC VERMA-CIRCULAR MOTION-Exercises
  1. A stone is fastened to one end of a string and is whirled in a verticl...

    Text Solution

    |

  2. A ceiling fan has a diameter (of the circle through the outer edges of...

    Text Solution

    |

  3. As mosquito is sitting on an L.P. record disc rotating on a turn table...

    Text Solution

    |

  4. A simple pendulum is suspended from the ceilling of a car taking a tru...

    Text Solution

    |

  5. The bob of a simple pendulum of length 1 m has mass 100 g and a speed ...

    Text Solution

    |

  6. Suppose the bob of the previous problem has a speed of 1.4 m/s when th...

    Text Solution

    |

  7. Suppose the amplitude of a simple pendulum having a bob of mass m is t...

    Text Solution

    |

  8. A person stands on a spring balance at the equator. a.By wht fraction ...

    Text Solution

    |

  9. A turn of radius 20 m is banked for the vehicles going at a speed of ...

    Text Solution

    |

  10. A motorcycle has to move with a constnt speed on an overbridge which i...

    Text Solution

    |

  11. A car starts rest, on a horizontal circular road of radius R, the tang...

    Text Solution

    |

  12. A block of mass m is kept on a horizontal ruler . The friction coeffic...

    Text Solution

    |

  13. A track consists of two circular pars ABC andCDE of equal rdius 100 m ...

    Text Solution

    |

  14. In a children's park a heavy rod is pivoted at the centre and is made ...

    Text Solution

    |

  15. A hemisphericla bowl of rdius R is rotated about its axis of symetry w...

    Text Solution

    |

  16. A particle is projected with a speed u at angle theta with the horizon...

    Text Solution

    |

  17. What is the radius of curvature of the parabola traced out by the proj...

    Text Solution

    |

  18. A block os mass m moves on as horizontal circle against the wall of a ...

    Text Solution

    |

  19. A table with smooth horizontal surface is fixed in a cabin that rotate...

    Text Solution

    |

  20. A car moving at a speed of 36 km/h is taking a turn on a circular roa...

    Text Solution

    |