Rock Climbing: Work Done by Gravity & Change in GPE

AI Thread Summary
The discussion revolves around calculating the work done by gravity and the change in gravitational potential energy (GPE) for a rock climber with a mass of 92.1 kg who climbs a height of 33.8 m. The work done by gravity can be determined using the formula W = -mgh, where h is the height climbed. The change in GPE is calculated using the equation ΔPE = mgh, which reflects the energy gained as the climber ascends. Participants emphasize understanding the signs of work based on the direction of forces and motion. The conversation highlights the importance of grasping these fundamental concepts in physics.
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Homework Statement



A rock climber of mass 92.1 kg starts at the base of a cliff and climbs to the top (h = 33.8 m). He then walks along the plateau at the top for a distance of L = 289.9 m.

(a) Find the work done by gravity.
(b) What is the change in the gravitational potential energy of the rock climber.


Homework Equations



Im still learning this stuff and am clueless thus far.

The Attempt at a Solution



This is why i need help..

THANKS!
 
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This problem is very similar to the others you have posted so far. Look at the solutions to those and you should be able to figure out this one.
 
I'm trying. I understand PE=mgy but it just isn't working for me.
 
Consider the fact that that work can have a positive or negative sign, depending on if the force is working in the same or opposite direction of motion.
 

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