# Homework Help: Average Velocity

1. Feb 23, 2006

### physhelp

How do you find average velocity by reading off of a data graph?

2. Feb 23, 2006

### dicerandom

That depends, is it a graph of position versus time, velocity versus time, or acceleration versus time?

3. Feb 23, 2006

### physhelp

it is d(m) vs t(s).....so it is distance versus time

4. Feb 23, 2006

### dicerandom

When you have a distance versus time graph the velocity at any given point is the slope of the line at that point. If you have a number of different velocities on the graph you'll want the weighted average, i.e. take each velocity, multiply it by the ammount of time the particle had that velocity, add them all up, then divide by the total time.

5. Feb 23, 2006

### physhelp

ok thanks a lot

6. Feb 23, 2006

### dicerandom

It just occured to me that I made this a lot harder than it needed to be

I was thinking of the whole matter in terms of a velocity vs. time graph, which is why I was talking about slopes of your distance vs. time graph. The easy way to do this is to simply subtract the initial value for the position from the final value for the position then divide by the time. That's really the same thing as what I said above, except it's computationally much more simple.