Yes. As long as the inital and end positions are different, you will have a nonzero average velocity.
An object moving in a circular path at constant speed will have a non-zero average speed and zero average velocity since velocity is a vector parameter,
i will give u an illustration, consider an object projected (thrown)with some initial vertical velocity from the ground such that it traces a open downward parabolicpath, in that path the vertical displacement of the body from the point of projection to the point where it strikes the ground is equal to zero,but it have some velocity.
The velocity at each point in the fluid is a vector. If the fluid is compressible, the divergence of the velocity vector is nonzero in general. In a vortex the curl is nonzero.
Yes, but only for an instant.
No because velocity defined as speed in a given direction so if speed is 0 then velocity must also be 0
its velocity will change by accelerating in the direction of the force
For the instantaneous value of average velocity, average speed and average velocity are equal.
polar
Velocity is speed and its direction. Average velocity is average speed and its direction.
Yes. An object moving at constant velocity has zero acceleration. The constant velocity van be any constant including zero velocity. Mathematics acceleration a=dv/dt = 0. Solving this gives v = constant.
Yes, for example, a car moving at constant speed.
speed is a scalar quantity with magnitude only but no direction; velocity is a vector with both magnitude (speed) AND direction, which could be positive or negative