Gravitational Potential Energy of a skateboard

[galtspeaking]

Homework Statement

[PLAIN]https://dl.dropbox.com/u/9215647/webassign%20s.JPG

Rank the slopes (greatest first) according to the work done on the skater by the gravitational force during the descent on each slope,

Homework Equations

work=change in potential energy, ie. delta U = mg*(delta)h

The Attempt at a Solution

since potential energy is greatest at slope 1, shouldn't the rank be 1,2,3? but that is wrong..what am I doing wrong in this question then?

 

[SammyS]

The change in height is the same for all three slopes. What does that tell you about the change in potential for each?

 

[galtspeaking]

ah, I see..so they are all the same, b/c mgh is the same for all of them,

i was considering the total height each of the slopes from the origin, i think that's where i was wrong

 

[SammyS]

Correct!