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No, work done only cares about the start and the end. What happened in-between doesn’t matter.

In this case, the kinetic energy is 0 at the start and end, but the potential energy of the mass increased by mgh. 5 kg * 9.81 m/s^2^ * 2 m = 98.1 J (1 J = 1 N•m).

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jjj@lemmy.blahaj.zone ⁨1⁩ ⁨week⁩ ago
Your equations are correct (although as I said in my other comment 9.81 is the global average but gravity varies by ~0.1 so that’s too many significant figures), but their issue doesn’t have to do with using sloped distance (they don’t as far as I can tell). It says the height change is 2 meters, and they use 2 meters as the distance since that’s the component of the displacement parallel to gravity. The problem is that they didn’t convert mass to weight.

work = force • displacement = |force| * |displacement| * cos(angle between them) = component of force parallel to displacement * |displacement| = component of displacement parallel to force * |force| weight = force due to gravity = mass * acceleration due to gravity ≈ 5 kg * 9.8 m/s² = 49 N
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- glibg10b@lemmy.ml ⁨6⁩ ⁨days⁩ ago
  OP specifically asked about the sloped distance:
  
  Shouldn’t the slopped distance be considered instead of the height?
  
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  - jjj@lemmy.blahaj.zone ⁨5⁩ ⁨days⁩ ago
    Ah, my mistake.
    
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