Explain how a vector field F= (f,g,h) is used to describe the motion of the air in a room at one instant in time.
A. The gradient of F = 〈f,g,h) evaluated at (x,y,z) is the velocity vector of an air particle at (xyz) at a fixed point in time.
B. F=(f.g,h) evaluated at (x.y,z) is the velocity vector of an air particle at (x.y,z) at a fixed point in time
C. F=(f.gh) evaluated at (x,y,z) is the location vector of an air particle at (xyz) at a fixed point in time.
D. The gradient of F=(f,g,h) evaluated at (xy,z) is the location vector of an air particle at (xy,z) at a fixed point in time