# Homework Help: Constant Velocity Confusion

1. Sep 30, 2008

### Robershky

I am doing make-up questions from my General Physics test. This is pretty easy stuff, and I thought I answered correctly, but according to my teacher's comments on my paper it seems like I'm missing something.

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

For the data provided, is the velocity for this object constant? How do you know?

Displacement (cm): 15, 100, 190, 290, 380
Time (seconds): 0, 3, 6, 9, 12

2. Relevant equations

3. The attempt at a solution

Just by looking at the data I would say it's not constant, but after graphing it, the trend curve is linear, so I wrote my answer as

Is there any other way to explain the fact that the data is linear?

2. Sep 30, 2008

### Sheneron

I sure would be curious to find out what exactly your teacher wants.

3. Sep 30, 2008

### peleus

Yes, because the trend curve is linear and... you're a great teacher?

4. Sep 30, 2008

### PhanthomJay

Hint: If the line had a significant slope, the v-t graph would still be linear, but the velocity would not be constant (the object would be accelerating).

5. Sep 30, 2008

### Robershky

But the graph is for position vs time, which is linear. Therefor the Velocity vs. Time graph would have a slope of 0, making it constant velocity.

6. Sep 30, 2008

### PhanthomJay

You're right, i messed that up big time. So I guess you could say "linear with a slope of v'?

7. Sep 30, 2008

### Robershky

PhanthomJay: Yeah, I guess the only information I could add is the trend line equation or the slope value. I guess I'll add that and hope it's good enough, thanks.