- #1
wuwei
- 2
- 0
according to continuity equation (partial ρ)/(partial t) +divergence J = 0 . there is such a situation that there is continuous water spreads out from the center of a sphere with unchanged density ρ, and at the center dm/dt = C(a constant), divergence of J = ρv should be 0 anywhere except the center, but if I think that at the origin the density of water is unchanged and so the first term of continuity equation is 0 so divergence J is 0, too. but apparently it's wrong. what's the problem?