What are the key concepts to consider when analyzing motion on an incline plane?

[TexasCow]

Homework Statement

I've got this lab I'm working on and I'm somewhat confused. We pushed a roller cart up an incline plane to determine acceleration and the such. Here is the graph.
http://img231.imageshack.us/img231/7950/physicslabpicsh5.png

Homework Equations

The questions I have are:
-Make a diagram of the track and show how to determine the angle of slope from your track height readings. calculate a value for Agsin(theta). Compare this to your overall acceleration.
-From looking at the graph would you classify motion on an incline as accelerated or unacceleration motion?
-How can you identify what interval the cart was freely moving?
-Compare up and down values for acceleration. Why are they different?
-From vales for angle, up, and down acceleration, determine the effective coefficient of friction for the motion cart.

The Attempt at a Solution

1. I assume this would be (9.8)(height/length)
2.Accelerated (negative) due to the force of friction acting against the cart which results in decreased velocity, aka varying acceleration.
3.Freely moving when the line is straight
4.Different due to slope of the incline?
5.getting to this one...

Can anyone guide me in the right direction?

 

[learningphysics]

Can you describe the experiment a little more? Why does the position come down and go back up?

 

[TexasCow]

Well bascially there is a cart on rollers that you push up towards a motion sensor, then it rolls back down. The data is analyzed by Logger Pros software on a laptop.

 

[learningphysics]

Well bascially there is a cart on rollers that you push up towards a motion sensor, then it rolls back down. The data is analyzed by Logger Pros software on a laptop.

So is position on your diagram height?

Reason I ask is because in what you describe, height should go up, then come back down, but in your diagram position goes down then goes back up.

 

[TexasCow]

I'm pretty sure position is the distance from the motion sensor, and is the y-axis on the first graph.