You are standing on a straight stretch of road and watching the motion of a bicycle; you choose your position as the origin. At one instant, the position of the bicycle is negative and its velocity is positive. Is the bicycle getting closer to you or farther away? Explain.

Answer: Ok, if the position of the bicycle is negative, then you can think is in the - x range, lets call it - r.

And the velocity is positive, you know that the movement equation of something is x = v*t + x0

where v is te velocity, x0 the position and t the time.

so in our case x = v*t - r.

so when v*t = r, for some time, the bicycle will be on your position.

So the bicycle was getting closer to you.