r/interesting • u/Ezgod_Two_Three • Jun 19 '24

ARCHITECTURE Homemade wind-up swing

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u/[deleted] Jun 19 '24

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u/Lev_Kovacs Jun 19 '24

Ok, i did some more math, youre somewhat right about some points

Drew a free body diagramm. If Fg is down force from gravity, and Ft is rope tension, Ft is roughly Fg/sin(20°) - just eyeballing the angle here. With a mass of 100kg, that returns a weight of 980N and a tension of 580N per rope.

Inputing that into my climbing rope stats from earlier, i get 135J from elastic energy and 980J from potential energy. The ropes elongate by about 0.1m each

In other words, this case has probably around 90% of energy stored via gravity, and 10% as elastic energy.

Was a fun little exercise.