### Home > CALC > Chapter Ch2 > Lesson 2.2.2 > Problem 2-72

2-72.

Notice what each axis represents.

negative acceleration = decreasing velocity. The first time this happens is between *t* = 2 and *t* = 4. When else does this happen?

On what interval is Tiffani's velocity increasing the most? Remember, this is a velocity graph.

0 acceleration means that velocity is not changing. It does NOT mean that velocity is 0. What does it mean then? Notice that Tiffani was moving with 0 acceleration during three intervals on her journey.

Displacement can be determined by calculating the area under a velocity curve.