Displacement-Time Graph - ??????

[ABCCBA]

How would the instantaneous velocity of the point of intersection between the first line and the second line be calculated? Would I take the slope of the tangent for that point, or would it be accepted as both the constant speed of the first line and the second line? How would the instantaneous velocity of the point at 0 minutes be calculated? When answering a question with regards to 'When was its speed constant', would I refer to the first time period as 0 to 6 including both 0 and 4, 0 to 6 including 4 and excluding 0, 0 to 6 including both 4 and 6 or 0 to 6 including 0 and excluding 4; if instantaneous speed is not constant throughout the time period, it should be assumed that speed is not constant at certain point/s.

[jamonwindeyer]

Hi!

How would the instantaneous velocity of the point of intersection between the first line and the second line be calculated?
I don't think those two sloped lines intersect for positive time

How would the instantaneous velocity of the point at 0 minutes be calculated?
Slope of the line at that point! It's a straight line so this is easy, so just rise over run (1.5 miles in 3 minutes, so 0.5 miles per minute!)

When answering a question with regards to...
I'm guessing I am missing some info here based on your wording? That said, I would say the speed is constant for all points in this graph, except the corner points. In the corner points the velocity changes, but besides that, the lines are all straight, meaning the slopes are all constant, meaning the speed is constant everywhere (except the corner points where it does change at that instant)