# Homework Help: Velocity versus time graphs

1. Jul 13, 2009

### alex2256

OK, on a velocity-time graph, how does one determine the acceleration?

I actually attempted to find the slope of the line and the graph here:

http://www.physicsclassroom.com/Class/1DKin/U1L4a.cfm (the second graph with the rightward changing velocity) Why does it graph 4, 8, 12, 16 and 20 instead of the 2, 8, 18, 32 and 50 on the velocity axis?

If I find the slope of the line I get 2, 4, 6, 8, 10 which to me looks like constant acceleration and not rightward changing acceleration. Can anybody help me?

Thanks for the help.

2. Jul 13, 2009

### negitron

One of these statements does not match the description in the link.

3. Jul 13, 2009

### alex2256

I'm sorry, I meant "rightward changing velocity". In the second graph on that page from the top, they graph 4, 8, 12, 16 and 20 and not the numbers 2, 8, 18, 32 and 50. Am I missing something blatantly obvious here, or?

4. Jul 13, 2009

### negitron

Well, does a changing velocity necessarily imply a changing acceleration?

5. Jul 13, 2009

### alex2256

Would I need to find the average acceleration by minusing the initial velocity from the final velocity divided by the final time minus the initial time to get 4m/s^2?

6. Jul 13, 2009

### negitron

Why? Does the slope of the line change?

7. Jul 13, 2009

### alex2256

Oh.. do you mean I could simply find the slope of the line and that is my acceleration, since the slope of a line is the acceleration of an object on a v-t graph?

8. Jul 13, 2009