On the infringement of the law of the pendant while solving the problems of the theoretical mechanics

Authors

  • L. M. Bondarenko к.т.н., доц., Ukraine
  • О. Е. Sevastianova к.т.н., доц., Ukraine
  • А. S. Bondarenko student, Ukraine
  • Е. О. Ponomarova student, Ukraine

Keywords:

Coulomb law, brake pads, normal pressure, angle of girth

Abstract

Abstract. Objective. Set degree of inaccuracy in solving problems with cylinders in view of their weight and pulley pressing pads at equilibrium conditions with regard to the amount of pressure normal and common. Methodology. Almost all Problems in theoretical mechanics there are problems on the balance cylinders opirajut on the surface of the same radius as the cylinder or cylinders of the problem (pulley) held in equilibrium pressing pads. In textbooks for students is important to avoid uncertainty in the problem or solution that knowledge acquired in universities are perceived as truth. Results. It is proved that the force pressing the brake pads to the brake pulley is not equal to the power of atmospheric pressure as suggested above formulas use only the angles of coverage not exceeding 45 . Scientific novelty. Angle of coverage in the cylinder leaning on a curved support or circumference of the cylinder brake pads should be considered when β> 45  because ignoring angle results in a significant breach of Coulomb's law, which takes into account the normal force.

Author Biographies

L. M. Bondarenko, к.т.н., доц.

Department of theoretical mechanics, State Higher Educational Institution «Prydniprovs’ka State Academy of Civil Engineering and Architecture», 24a, Chernyshevs’kogo St., Dnipro, Ukraine

О. Е. Sevastianova, к.т.н., доц.

Department of theoretical mechanics, State Higher Educational Institution «Prydniprovs’ka State Academy of Civil Engineering and Architecture», 24a, Chernyshevs’kogo St., Dnipro, Ukraine

А. S. Bondarenko, student

Department of theoretical mechanics, State Higher Educational Institution «Prydniprovs’ka State Academy of Civil Engineering and Architecture», 24a, Chernyshevs’kogo St., Dnipro, Ukraine

Е. О. Ponomarova, student

Department of theoretical mechanics, State Higher Educational Institution «Prydniprovs’ka State Academy of Civil Engineering and Architecture», 24a, Chernyshevs’kogo St., Dnipro, Ukraine

References

Kozhevnikov S.N. Teoriya mehanizmov i mashin. – M.: mashinostroenie, 1969.– 584 s.

Mescherskiy I.V. Sbornik zadach po teoreticheskoy mehanike. – M.: Nauka, Glavnaya redaktsiya fiziko-matematicheskoy literaturyi, 1981. – 480 s.

Bat M.I., Dzhamelidze G.Yu., Kelzan A.S. Teoreticheskaya mehanika v primerah i zadachah. – M.: Glavnaya redaktsiya fizikomatematicheskoy literaturyi, 1984. – 504 s.

Brazhnichenko N.A., Kan V.L., Mintsberg B.L., Morozov V.I. Sbornik zadach po teoreticheskoy mehanike. – L.: Sudpromgiz, 1961. – 560 s.

Published

2017-03-28

Issue

Section

Proceedings in memory of Starodubov