Gravitational Potential Energy of a skateboard

AI Thread Summary
The discussion focuses on ranking slopes based on the work done by gravitational force on a skateboarder during descent. The key equation used is the change in potential energy, represented as delta U = mg*(delta)h. It is clarified that since the change in height is the same for all slopes, the potential energy change is also identical across them. The initial assumption that the slopes should be ranked by their individual heights was incorrect. Ultimately, all slopes result in the same work done due to equal changes in height.
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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?
 
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The change in height is the same for all three slopes. What does that tell you about the change in potential for each?
 
ah, I see..so they are all the same, b/c mgh is the same for all of them,

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

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