The equation a vt u vx v vy w vz represents a the change

The equation a = v/t + u v/x + v v/y + w v/z represents a) the change in volume of a system with respect to time and space b) a vector expression for a Cartesian coordinate system c) similarity d) the acceleration of a fluid particle in unsteady flow Local acceleration: a) is time dependent. b) is zero for unsteady flow. c) is equal to the convective acceleration. d) none of the above. A line consisting of all particles in a flow that have previously passed through a common point is a: a) streamline b) steakline, c) pathline d) none of the above

Solution

18-(d) present equation of acceleration for a general flow.for steady flow the first term will be 0.

19-(a) local acceleration is equal to rate of change of velocity with respect to time

20-(b) streak line e.g. smoke of chimney ,cigarette.