Gravitation potential energy question helpby jbjohnybaker Tags: earth, gravity, mgy, physics, potentital 

#1
Apr2011, 07:22 PM

P: 19

1. The problem statement, all variables and given/known data
A 68.5kg skier rides a 2.56km ski lift from the base of a mountain to the top. The lift is at an angle of 13.9° to the horizontal. Determine the skier’s gravitational potential energy at the top of the mountain relative to the base of the mountain. 2. Relevant equations Eg= mg delta y 3. The attempt at a solution eg = (68.5)(9.81)(2560) = 1720281.6 J The answer in the textbook is 4.13x10^5 J :S 



#2
Apr2011, 07:36 PM

P: 242

hello,
you have not accounted for the angle. the ski lift does not go straight up, it goes up a slope. 



#3
Apr2011, 07:42 PM

P: 19





#4
Apr2011, 07:45 PM

P: 242

Gravitation potential energy question help
that is correct, but you have the wrong value for delta y. the lift travels a total distance of 2.56 km, but that is not the change in altitude, that is how long the cables are.




#5
Apr2011, 07:49 PM

P: 19

eg = (68.5)(sin13.5)(9.81)(2560) 



#6
Apr2011, 07:50 PM

P: 242

looks good.




#7
Apr2011, 07:53 PM

P: 19

thank you very much.




#8
Apr2011, 07:58 PM

P: 242

cheers.



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