I recently came across this question :
What will be the effect on inertia if -
- density is halved - volume is one third
I searched about it but everywhere found the answer that there will be no effect on inertia. But i fell this is wrong. The reason given was that inertia depends on mass, which is not changed. But
Mass = density × volume
It means that mass is directly proportional to density and volume. So if density or volume is decreased, then mass should also decrease and hence inertia SHOULD decrease.
Am i right ? Why ?
Edit : one more question arised that should we consider the mass to be conserved (even if its not mentioned in the question) why ?