Velocity is always a scalar, instantaneous or average doesn't matter.
"Velocity" is a vector quantity. This also applies to instantaneous velocity. If you want the scalar quantity, you talk about "speed".
vector.
Because speed is the magnitude of the velocity vector. The velocity consists of the speed and the direction, and the whole thing can be embodied in a 3D vector. If you like the velocity is the magnitude (the speed), which is a scalar (just a real number), multiplied by a unit vector in the right direction.
"Speed" is a scalar; "velocity" is a vector.
vector
Velocity is a vector.
velocity is a vector and speed is a scalar.
velocity is a vector and speed is a scalar.
scalar=speed time vector=velocity force
Momentum is defined as the product of a particle's mass and velocity. Mass is a scalar and velocity is a vector, the multiplication of a scalar and vector always results in a vector.
Velocity and acceleration are both vector quantities.
Velocity is a vector quantity or simply vector, it has both magnitude an direction.