Roller Coaster Problem with KE and PE

[chris61986]

Homework Statement

https://dl.dropbox.com/u/92857534/physicsproblem.png

Note: Solving for part D and E

Homework Equations

Unsure. language in the problem seems ambiguous.
Perhaps (KE + PE)b = (KE + PE)a

The Attempt at a Solution

So I think it's done this way.

From A to B and B to C, the equation would look this way:
PEb + KEb = KEa + PEa
PEa = 0, move KEb to right side, left with:
PEb = KEa - KEb
so WGH = 1/2mv'^2 - 1/2mv^2

Am I going the right way about this? If so, where do I go from here when I don't know both velocities?
Also, for parts A, B, and C, it's simply W = mgΔh, correct? I'm not used to things being easy :P

 

[mukundpa]

Work energy rule says that the increase in kinetic energy of a body is equal to work done on it.

 

[chris61986]

Do you think you could be a little less cryptic?

 

[mukundpa]

Work done by gravity is equal to the increase in kinetic energy of the car. The same is the loss in potential energy. W = mgΔh is correct.
In second part I think potential energy is to be calculated at different points.