Question

Two wheels A and B are mounted on 6 kg `m^(2)` the same shaft. One of them having their moment of inertia 8 kg `m^(2)` with the angular speed 600 rpm and other is at rest. The value of moment of intertia of another wheel in order to achive the combined angular speed 300 rpm is
A. 4 kg `m^(2)`
B. 3 kg `m^(2)`
C. 6 kg `m^(2)`
D. 9 kg `m^(2)`

Answer 1

c) From the conservation of angualr momentum,
`(l_(1) + l_(2))omega = I_(1)omega_(1) + I_(2)omega_(2)`
`rArr (6+I_(2)) xx (300)/(60) xx 2pi = 6 xx (600)/(60) xx 2pi xx I_(2) xx 0)`
`rArr I_(2) = 6kg m^(2)`