# Homework Help: Easy Questions - Plz Help

1. Mar 16, 2005

### bigbasherboy

what is the physical meaning of the sign of the area under a velocity v. time graph (displacement) ??

what is the physical meaning of the sign of the area under a acceleration
v. time graph (velocity) ??

plz help me

Last edited: Mar 16, 2005
2. Mar 16, 2005

### HallsofIvy

I'm not quite sure what you mean: area is always positive. Assuming you mean "signed" area (a bit of a strange terminology), the area under the velocity v time graph is "displacement"- distance moved. If that is positive, then you have moved in the positive direction, if negative you have moved in the negative direction.

"Area" under the acceleration v time graph is change in speed. If that is positive, speed has increased, if negative, speed has decreased.

3. Mar 16, 2005

### bigbasherboy

ok i see, but lets say we have negitive displacement, does that mean the "area" would be graphed below the x-axis on a graph ?

4. Mar 16, 2005

### xanthym

Yes, because velocity "v" would be negative ("under the x-axis"), and the integral would yield a negative value (or "area") for displacement.

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