Acceleration is a vector quantity. Is force a vector quantity, too?

If a body traverses a distance in direct proportion to the time, the speed of the body is _____.

(stationary, zero, changing, constant, displacement, velocity, speed, acceleration, stationary but not zero, increases)

If a body is moving with a constant velocity its acceleration is _____ (zero, changing).

_____ is the distance traversed by a body in a particular direction in unit time. 

(stationary, zero, changing, constant, displacement, velocity, speed, acceleration, stationary but not zero, increases)

Observe the figure and answer the questions.

Sachin and Sameer started on a motorbike from place A, took the turn at B, did a task at C, travelled by the route CD to D and then went on to E. Altogether, they took one hour for this journey. Find out the actual distance traversed by them and the displacement from A to E. From this, deduce their speed. What was their velocity from A to E in the direction AE? Can this velocity be called average velocity?