Consider a model of finite control volume (volume V and surface area) fixed in space with elemental volume dV, vector elemental surface area d\(\vec{S}\), density ρ and flow velocity \(\vec{V}\).\(\rho\vec{V}.d\vec{S}\) is positive when _____________

• A. fixed in space with elemental volume dV, vector elemental surface area d\(\vec{S}\), density ρ and flow velocity \(\vec{V}\).\(\rho\vec{V}.d\vec{S}\) is positive when _____________a) The mass flow is outward
• B. The mass flow is inward
• C. The mass flow is positive
• D. The mass flow is negative