Question

A `40 kg` flywheel in the from of a uniform circular disc of `1 m` radius is making `120` rpm. Calculate the angular momentum.

Answer 1

Here, `M=40 kg,R=1m,v=120 "rpm" = (120)/(60) rps`
`rArr` Frequency, `v=2` rps
Therefore, `I = (1)/(2)MR^(2)=(1)/(2)xx40xx(1)^(2)=20 "kgm"^(2)`
and `omega = 2piv = 2pixx2 = 4 pi "rads"^(-1)`
So, angular momentum, `L=Iomega=20xx4pi=20xx4xx3.14`
`L=251.2 "kgm"^(2)s^(-1)`.