Question

Failing to integrate: rho . u [(del u/del x) . dx + (del u/del y) . dy + (del u/del z) . dz ]. The answer is rho. d(u^2 / 2). But I dont know how to get there. please help. Thank you.

Answer 1

[(del u/del x) . dx + (del u/del y) . dy + (del u/del z) . dz ] = du (x,y,z)
so we have rho . u . du
can also be written as rho d (\[u ^{2}/2\])