Question

a body start rotating from rest.due to couple of 20 Nm it completes 60 revolution in 1min.find moment of inertia of the body ?​

Answer 1

T = 20 N m,

n = 60 revolutions in 60s = 1 r.p.s. ,

t = 1 min = 60s

Moment of inertia ( I ) = ?

Angular displacement θ=ωt=2πnt

= 2π×1×60

= 120π rad

θ=ω

o

t+

2

1

αt

2

120π=0+

2

1

α×60

2

α=

60

2

240π

=

15

π

rad/s

2

τ=Iα

I=

α

τ

=

15

π

20

= 95.48 kg m

2

Moment of inertia of the body is 95.48 kg m

2