Hi guys! My first post here. I've been frequenting Physics Forums and have found a wealth of information, and I'm hoping I can get some specific help about this concept. Thanks! 1. The problem statement, all variables and given/known data "Cart A and B move along a horizontal track. The top-view strobe diagram below shows the locations of the carts and instants 1-5, separated by equal time intervals." Cart A: o....o....o....o....o Cart B: o.o..o...o....o (The periods represent 1cm of distance, and Cart B's position at Instant 1 is 5cm ahead of Cart A. If you want a better depiction than my horrible attempt using o's and periods, here's a link to the graphic) "Is there any instant at which cart A and cart B have the same instantaneous velocity? If so, identify the instant(s) and explain. If not, explain why not." 2. Relevant equations I think this is more of a conceptual problem, so I don't think there are any relevant equations. However, [tex] v= v_0 + at [/tex] might be relevant. 3. The attempt at a solution So, I think the answer is that there's no way of determining when the instantaneous velocity is the same (the average velocity is the same for both from instance 4-5 because there is a 4cm difference between locations of cart A and B, and [tex] v_a =∆x/∆t[/tex], so they have the same average velocity) because instantaneous velocity is just dx/dt and I can't think of a way to find that w/o a function or a graph or something. I tried using [tex] v= v_0 + at [/tex] (for cart A: v_0=0, a=0, and t=5; for cart B: v_0=0, a=1, t=5), but I don't know if that will give me the instant(s) where the instantaneous velocity is the same. This is probably a really basic question and I have a feeling the answer's pretty obvious, but I'm not sure. If anyone could help me out, I'd really appreciate it. Thanks!