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Displaying 11-16 of 16 results found. ( prev )     page 1 2
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BP850 Shape can be maneuvered around the corner vs. not so.
(edit; present; nest [left/right]; search; history)
REFERENCE

https://en.wikipedia.org/wiki/Moving_sofa_problem

CROSSREFS

Adjacent-numbered pages:
BP845 BP846 BP847 BP848 BP849  *  BP851 BP852 BP853 BP854 BP855

KEYWORD

nice, precise, physics, creativeexamples, proofsrequired, left-narrow, right-narrow, dithering

CONCEPT rotation_required (info | search),
imagined_motion (info | search),
physically_fitting (info | search)

AUTHOR

Leo Crabbe

BP896 Filled completely by fluid poured into gap (assuming there is already air) vs. not so.
(edit; present; nest [left/right]; search; history)
COMMENTS

For a non-physics-based solution, "there exists a never-vertically-increasing path starting from the opening to each point in the interior vs. not so." - Aaron David Fairbanks, Aug 01 2020

CROSSREFS

Adjacent-numbered pages:
BP891 BP892 BP893 BP894 BP895  *  BP897 BP898 BP899 BP900 BP901

KEYWORD

nice, handed, updown, physics

CONCEPT liquid_flow (info | search),
gravity (info | search)

WORLD

[smaller | same | bigger]

AUTHOR

Zane Fry

BP933 Ball will reach edge of bounding box under gravity vs. not so.
(edit; present; nest [left/right]; search; history)
COMMENTS

Strictly this Problem's solution is not actually about gravity, it is about a constant downwards force (the ball's time-independent path does not depend on the magnitude of the force, only direction). The phrasing for the solution is a shorthand that takes advantage of human physical intuition.

CROSSREFS

Adjacent-numbered pages:
BP928 BP929 BP930 BP931 BP932  *  BP934 BP935 BP936 BP937 BP938

KEYWORD

physics

CONCEPT bounding_box (info | search),
imagined_motion (info | search),
gravity (info | search)

WORLD

dot_with_lines_or_curves [smaller | same | bigger]

AUTHOR

Leo Crabbe

BP1016 Rigid vs. not rigid.
(edit; present; nest [left/right]; search; history)
REFERENCE

Henneberg, L. (1911), Die graphische Statik der starren Systeme, Leipzig

Jackson, Bill. (2007). Notes on the Rigidity of Graphs.

Laman, Gerard. (1970), "On graphs and the rigidity of plane skeletal structures", J. Engineering Mathematics, 4 (4): 331–340.

Pollaczek‐Geiringer, Hilda (1927), "Über die Gliederung ebener Fachwerke", Zeitschrift für Angewandte Mathematik und Mechanik, 7 (1): 58–72.

CROSSREFS

Adjacent-numbered pages:
BP1011 BP1012 BP1013 BP1014 BP1015  *  BP1017 BP1018 BP1019 BP1020 BP1021

KEYWORD

nice, physics, help

CONCEPT rigidity (info | search),
graph (info | search),
imagined_motion (info | search)

WORLD

planar_connected_graph [smaller | same | bigger]
zoom in left (rigid_planar_connected_graph)

AUTHOR

Aaron David Fairbanks

BP1095 Angle of incidence equals angle of reflection vs. not
(edit; present; nest [left/right]; search; history)
REFERENCE

https://en.wikipedia.org/wiki/Specular_reflection

https://en.wikipedia.org/wiki/Snooker

CROSSREFS

Adjacent-numbered pages:
BP1090 BP1091 BP1092 BP1093 BP1094  *  BP1096 BP1097 BP1098 BP1099 BP1100

KEYWORD

easy, nice, precise, allsorted, physics, perfect

AUTHOR

Jago Collins

BP1256 Arrows which if moved at speeds proportional to their length would pass eachother vs. not so
(edit; present; nest [left/right]; search; history)
CROSSREFS

Adjacent-numbered pages:
BP1251 BP1252 BP1253 BP1254 BP1255  *  BP1257 BP1258 BP1259 BP1260 BP1261

KEYWORD

precise, physics, unorderedpair, traditional

CONCEPT arrow (info | search)

AUTHOR

Matt Samuels

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