Physics 11 work done by friction

AI Thread Summary
To determine the work done by friction on Magen, first calculate her mechanical energy at the top of the slide using the potential energy formula (Ep = mgh) and at the bottom using kinetic energy (Ek = 1/2mv^2). The difference in mechanical energy between the top and bottom indicates energy lost to friction. The discussion emphasizes tracking mechanical energy and suggests using the equation Eki + Epi = Ekf + Epf to relate the energies. The final calculated work done by friction is approximately 1.2 x 10^3 Joules.
Iceclover
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Homework Statement



Magen's mass is 28kg. she climbs the 4.8m ladder of a slide and reaches a v3elocity of 3.2m/s at the bottom of the slide. How much work was done by friction on Magen

Homework Equations



Ep=mgh
Ek=1/2mv^2
W=Fd

The Attempt at a Solution


I really just have no idea, could someone just guide me in the right direction or give me the first step?
 
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Think about the following things:
  1. How much mechanical energy does she have at the top of the slide?
  2. At the bottom of the slide?
  3. What could have happened on the slide that would have changed the mechanical energy?
 
Just keep track of the mechanical energy. If any is missing, assume it was lost to friction. What's her energy at the top? At the bottom? Subtract!

(Saketh beat me too it! :smile: )
 
so would i use Eki+Epi=Ekf+Epf?
 
oooh ok i think i get it...i think. The answer i came up with was 1.2x10^3
 
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