Homework Help: Finding the greatest distance from the origin given a velocity vs. time graph.

1. Oct 2, 2009

1irishman

1. The problem statement, all variables and given/known data
If given a velocity vs. time graph where max. constant velocity is 2m/s for 2s and the object turns around at 4s with max negative constant velocity is -2m/s for 2s. How do i find the greatest distance from the origin?

2. Relevant equations
d= vi+vf/2 *t
d=vit + 1/2at^2

3. The attempt at a solution
i'm really not sure what to do here...please hints?

2. Oct 3, 2009

Delphi51

Okay, so you have constant speed for the first two seconds and the distance increases steadily at d = vt. Then the direction reverses and the distance diminishes to zero over the next 2 seconds. The greatest distance is pretty clear . . .

3. Oct 3, 2009

is it 5m?

4. Oct 3, 2009

1irishman

is there a formula to help figure this out from just looking at a v-t graph coordinates?

5. Oct 3, 2009

Delphi51

Terribly sorry, I didn't see the bit about "turning around at 4s". Now I don't understand it because there is no indication of what happens between 2 and 4 seconds.

If you are looking at the graph, I suggest you find the distance travelled up to the turnaround time of 4 seconds. The area under the graph is the distance. Or use d = vt for the first 2 seconds and whatever is appropriate for the next two.