# Homework Help: Acceleration in 1 dimension (Conceptual)

1. Sep 23, 2008

### skwz

1. The problem statement, all variables and given/known data

Two cars C and D travel in the same direction on a long, straight section of a highway. During a particular time interval $$\Delta$$t0, car D is ahead of car C and speeding up while car C is slowing down.

During the interval $$\Delta$$t0, it is observed that C gains on car D (i.e.e the distance between the cars decreases. Explain how this is possible.

3. The attempt at a solution
I'm not sure, but what I thought was that if car C gains distance and slowing down, the change in its velocity (acceleration) over the very beginning of this time interval is lower than cars D acceleration in that beginning of the time interval. That way car C maintains the relatively same velocity for that small time period and can "gain". But then if car D is accelerating at a greater rate, then how could car C gain on car D? Can we assume the initial and final velocities differ for each car? I'm very confused.

2. Sep 24, 2008

### Kurdt

Staff Emeritus
The answer is very simple. If car D is ahead and speeding up, and car C is slowing down but the gap decreases then how must the velocities of the two compare? That is, which has the greater velocity?

3. Sep 24, 2008

### skwz

Cart C. Wow that was very simple... thanks