English Title

On the brachistochrone in a resistant medium while a body is attracted to a center of forces in one way or another

Authors

Leonhard Euler

Enestrom Number

761

Fuss Index

382

Original Language

Latin

Content Summary

Euler takes a look at the friction brachistochrone, where the force attracts a body to some point in space. Using polar coordinates, Euler calls O the attraction point and X an arbitrary point for which the centripetal force is x. Lastly he defines y, the angle between the initial point A, O and X, with p=dy/dx. Using the general isoperimetric theorem, derived in E760, Euler finds that ω dv/v + ω dV/V − Cvωt dV/V + [(Vω−X)/(VV)]∙(Cvt dVCVv dtdVV dv/v) = 0, where ω=√(1+ppxx), t=√((1+ppxx)/(pxx)) and C is some constant. Reducing this equation, Euler finds -1/(CVv) + t/V − ∫ω dt/X = Δ for some Δ. Using a relation between v and p, this curve can then be found explicitly.

Published as

Journal article

Published Date

1822

Written Date

1780

Original Source Citation

Mémoires de l'académie des sciences de St.-Petersbourg, Volume 8, pp. 41-45.

Opera Omnia Citation

Series 1, Volume 25, pp.338-342.

Record Created

2018-09-25

E761en.pdf (220 kB)
E761en.pdf (220 kB)

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