? ? ? ++++ ++++ ++++ ++++ ++++ Concept Question ++++ ++++ ++++ ++++ ++++ The following expression is the right statement of linear momentum balance for a deforming body of an arbitrary material: ?v ρ dV = f dV + n · σdS (1) V ?t V S ?v + v ·?v = ??p + μ? 2 v + f (2) ? ?t ? ? D ρx × vdV = x × f dV + x × tdS (3) Dt V V S ?v ?· σ + f = ρ (4) ?t 1. ++++ Eqn.(1) and Eqn.(3) 2. ++++ Eqn.(2) and Eqn.(4) 3. ++++ Eqn.(1) and Eqn.(4) 4. ++++ Eqn.(3) 5. ++++ DKDU ++++ ++++ ++++ ++++ ++++ Answer ++++ ++++ ++++ ++++ ++++ The correct answer to the concept question is: 3. ++++ Eqn.(1) and Eqn.(4).