A wheel of moment of inertia `3 kg m^2` rotates about an axis passing through its centre and perpendicular to its plane. Its initial speed of rotation is given as 60 rad /s. Due to friction, the wheel comes to rest in 5 minutes. If the angular momentum (in kg `m ^2//s` ) of the wheel three minutes before it stops is x then provide your answer as `x/100`

Answer

`01.08`

Explanation

`I =3 kg m^2`
`omega_0 =60 rad//s`
we know,
`alpha =(omega-omega_0)/t`
after time `t=5 " min " =300s,omega=0`
`:. alpha = (0-60)/300 = - 1/5 rad//s^2`
3 min before stopping i.e., 2 min from starting.
`omega =omega_0 + alphat`
`=60 + (-1/5)xx120`
`=36 rad//s`
Now , `L=I_omega`
`=3xx36`
`:. L = 108 kg m^2//s`