Home
Class 11
PHYSICS
When 100 J of work is done on a fly whee...

When 100 J of work is done on a fly wheel, its angular velocity is increased from 60 rpm to 180 rpm. What is the moment of inertia of the wheel?

Text Solution

Verified by Experts

K.E=100 J,`n_(1)`=60 rpm =1 rps,`n_(2)`=180 rpm =3rps
Increase in kinetic energy `E=(1)/(2)I(omega_(2)^(2)-omega_(1)^(2))=(1)/(2)I(4pi^(2)n_(2)^(2)-4pi^(2)n_(1)^(2))`
`100=(1)/(2)I(4pi^(2).9-4 pi^(2)1^(2))=2pi^(2)I(9-1)=16pi^(2).I`
`therefore` momeny of inertia of the wheel I =`(100)/(16 mpi^(2))=0.633 kg m^(2)`
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • ROTATIONAL MECHANICS

    AAKASH SERIES|Exercise Very short answer type questions|40 Videos

  • ROTATIONAL MECHANICS

    AAKASH SERIES|Exercise Numerical Exercise (LEVEL-1)|18 Videos

  • ROTATIONAL DYNAMICS

    AAKASH SERIES|Exercise PRACTICE SHEET (ADVANCED) Integer Type Questions|7 Videos

  • SIMPLE HARMONIC MOTION

    AAKASH SERIES|Exercise ADDITIONAL PRACTICE EXERCISE (LEVEL - II)(PRACTICE SHEET (ADVANCED)) (INTEGER TYPE QUESTIONS)|3 Videos

Similar Questions

Explore conceptually related problems

Calculate the moment of inertia of a fly wheel, if its angular velocity is increased from 60 r.p.m. to 180 r.p.m. when 100 J of work is done on it.

A horizontal disc is freely rotating about a vertical axis passing through its centre at the rate of 100 rpm. A bob of wax of mass 20 g falls on the disc and sticks to it a distance of 5 cm from the axis. If the moment of inertia of the disc about the given axis is 2xx10^(-4)kg m^(2) find new frequency of rotation of the disc.

Knowledge Check

  • When 200J of work is done on a fly wheel its frequency of rotation increases from 4Hz to 9Hz . The M.I. of the wheel about the axis of rotation is

    A
    `0.15kgm^(2)`
    B
    `0.2kgm^(2)`
    C
    `0.22kgm^(2)`
    D
    `0.3kgm^(2)`

  • When 200J of work is done on a fly wheel its frequency of rotation increases from 4Hz to 9Hz. The M.I of the wheel about the axis of rotation is

    A
    `0.15kgm^(2)`
    B
    `0.2kgm^(2)`
    C
    `0.22kgm^(2)`
    D
    `0.3kgm^(2)`

  • when 200J of work is done on a fly wheel its frequency of rotation from 4Hz to 9Hz. The M.I. of thw wheel about the axis of rotation is

    A
    `0.15" kg m"^(2)`
    B
    `0.2" kg m"^(2)`
    C
    `0.22" kg m"^(2)`
    D
    `0.3" kg m"^(2)`

    • Similar Questions

    Explore conceptually related problems

    A horizontal disc is freely rotating about a vertical axis passing through its centre at the rate of 100 rpm. A bob of wax of mass 20 g falls on the disc and sticks to it a distance of 5 cm from the axis. If the moment of inertia of the disc about the given axis is 2xx10^(-4)kgm^(2) , find new frequency of rotation of the disc.

    A ballet dancer spins about a vertical axis at 60 rpm with arms outstretched. When her arms folded the angular frequency increases to 90 rpm. Find the change in her moment of inertia.

    If 484J of energy is spent in increasing the speed of wheel from 60 rpm to 360 rpm, the M.I of the wheel is

    If 484 J of energy is spent in increasing the speed of a wheel from 60 rpm to 360 rpm, the M.I. of the wheel is

    If 484 J of energy is spent in increasing the speed of a wheel from 60 rpm to 360 rpm, the M.I. of the wheel is

    Home
    Profile