Physics please help with Motion of Two Rockets?

Learning Goal: To learn to use images of an object in motion to determine velocity and acceleration.

Two toy rockets are traveling in the same direction (taken to be the x axis). A diagram is shown of a time-exposure image where a stroboscope has illuminated the rockets at the uniform time intervals indicated.

http://session.masteringphysics.com/problemAsset/1…

1) At what time(s) do the rockets have the same velocity?

at time t = 1 only

at time t = 4 only

at times t = 1 and t = 4

at some instant in time between t = 1 and t = 4

at no time shown in the figure

2) At what time(s) do the two rockets have the same acceleration?

at time t = 1 only

at time t = 4 only

at times t = 1 and t = 4

at some instant in time between t = 1 and t = 4

at no time shown in the figure

3) The motion of the rocket labeled A is an example of motion with uniform (i.e., constant) __.

and nonzero acceleration

velocity

displacement

time

4) The motion of the rocket labeled B is an example of motion with uniform (i.e., constant) __.

and nonzero acceleration

velocity

displacement

time

5) At what time(s) is rocket A ahead of rocket B?

before t = 1 only

after t = 4 only

before t = 1 and after t = 4

between t = 1 and t = 4

at no time(s) shown in the figure