The definition of average velocity is:

According to this definition, the vector average velocity is obtained by dividing a vector by a scalar.� Since the scalar () is always positive, this definition implies that the two vectors (�and ) have the same direction.� We would like to apply this definition to find the velocity at point D.� Then �and �in the definition correspond to an interval that spans point D, i.e., with an initial point just before point D and with a final point just after point D.

 

You indicated that the velocity vector at point D is zero.� According to the definition above, this means that the displacement vector for the interval that spans point D is also zero.� If so, then the initial and final points for the interval spanning point D must be at the same location.� Is this true?