## Conceptual Area Under Velocity-Time graph confusion

Hi all I have a confusion regarding a physics concept. When you consider area under graph (velocity time graph), if the area is below x axis, is the area considered to be negative?
For example, look at the attachment. There are 2 shaded areas. Let the area above x axis be A and area below x axis be B and ignore all the numerical values on the graph. Is the displacement A+B or A-B? I am very confused.
 PhysOrg.com physics news on PhysOrg.com >> Kenneth Wilson, Nobel winner for physics, dies>> Two collider research teams find evidence of new particle Zc(3900)>> Scientists make first direct images of topological insulator's edge currents
 Recognitions: Gold Member Science Advisor I can't see your attachment but I can say that you can treat areas under the x axis as negative (after all, the velocity IS negative, isn't it? - so a positive time times a negative velocity gives you a negative answer.). So A+(a negative)B is the total area. Alternatively, and less strictly mathematically, you can just subtract the areas underneath from the areas on top. Same answer, of course.
 The displacement is A-B, the distance is A+B.

Recognitions:
Gold Member

## Conceptual Area Under Velocity-Time graph confusion

 Quote by MikeyW The displacement is A-B, the distance is A+B.
Only if you neglect that areas below the x axis are negative.
 I don't agree, areas are always positive or zero.

Recognitions:
Gold Member