Question

pls explain the following equation...

F=v dm/dt
=v(ρAv)
=ρAv^2

what is the 2nd v in the bracket?? where does it come from??

Answer 1

that second v is for speed of fluid trough pipe cause you changed mass flow (dm/dt) with (rho A v) and if you do a dimension analysis kg m-3 m2 ms-1 you can see that it is valid interchange