Page 164 - index
P. 164
ɛɨɥɵɩ ɬɚɛɵɥɚɞɵ. Ⱥɥ Ʉԛɧɝɟ ɠԥɧɟ ɨɫɵ ɠԛɣɟɞɟɝɿ ɩɥɚɧɟɬɚɥɚɪԑɚ ɛɚɫԕɚ
ɠԝɥɞɵɡɞɵԕ ɠԛɣɟɥɟɪɞɿԙ ԥɫɟɪɿ ɫɵɪɬԕɵ ɤԛɲɬɟɪ ɛɨɥɵɩ ɬɚɛɵɥɚɞɵ. ȿɝɟɪ ɀɟɪ
ɦɟɧ Ⱥɣ ɠԛɣɟɫɿɧ ԕɚɪɚɫɬɵɪɫɚԕ, ɨɧɞɚ Ʉԛɧ ɠԥɧɟ ɩɥɚɧɟɬɚɥɚɪɞɵԙ ɨɥɚɪԑɚ ԥɫɟɪɿ
ɫɵɪɬԕɵ ɤԛɲ ɛɨɥɚɞɵ, ɚɥ ɀɟɪ ɦɟɧ Ⱥɣɞɵԙ ԧɡɚɪɚ ԥɫɟɪɿ ɿɲɤɿ ɤԛɲ ɛɨɥɚɞɵ.
ɇɶɸɬɨɧɧɵԙ ԛɲɿɧɲɿ ɡɚԙɵɧɚɧ ɬɭɵɧɞɚɣɬɵɧ ɿɲɤɿ ɤԛɲɬɟɪɞɿԙ ɫɢɩɚɬɬɚɪɵ:
- ɿɲɤɿ ɤԛɲɬɟɪɞɿԙ ɛɚɫ ɜɟɤɬɨɪɵ ɧԧɥɝɟ ɬɟԙ;
- ɿɲɤɿ ɤԛɲɬɟɪɞɿԙ ɤɟɡ ɤɟɥɝɟɧ ɨɫɶ ɠԥɧɟ ɤɟɡ ɤɟɥɝɟɧ ɧԛɤɬɟ ɚɪԕɵɥɵ ɚɥɵɧԑɚɧ
ɛɚɫ ɦɨɦɟɧɬɿ ɧԧɥɝɟ ɬɟԙ.
ɋɨɧɵɦɟɧ:
oo
¦F (i) F (i) 0 (6)
Ȼ S
Ɏɨɪɦɭɥɚɞɚԑɵ:
o ¦o o ) 0, (6ɚ)
MO 0.
M (i) ( FS( i )
ȻO
o ¦o o
MU
M (i) (FS(i) )
ȻU
Ԕɨɪɵɬɚ ɚɣɬԕɚɧɞɚ, ɞɢɧɚɦɢɤɚɞɚ ɤԛɲɬɟɪɞɿԙ ɛԧɥɿɧɭɿ ɟɤɿ ɬԛɪɞɟ ɛɨɥɚɞɵ:
ɚ) ɛɟɥɫɟɧɞɿ (ɚɤɬɢɜ) ɤԛɲɬɟɪ ɠԥɧɟ ɪɟɚɤɰɢɹɥɚɪ;
ԥ) ɫɵɪɬԕɵ ɠԥɧɟ ɿɲɤɿ ɤԛɲɬɟɪ.
2-ɬɚɪɚɭ. ɆȺɌȿɊɂəɅɕԔ ɇԚɄɌȿ ɀԤɇȿ ɆȿɏȺɇɂɄȺɅɕԔ ɀԚɃȿ
ԔɈɁԐȺɅɕɋɌȺɊɕɇɕԘ ȾɂɎɎȿɊȿɇɐɂȺɅȾɕԔ ɌȿԘȾȿɍɅȿɊȱ
§1. Ɇɚɬɟɪɢɹɥɵԕ ɧԛɤɬɟ ԕɨɡԑɚɥɵɫɵɧɵԙ ɞɢɮɮɟɪɟɧɰɢɚɥɞɵԕ ɬɟԙɞɟɭɥɟɪɿ
oo o
Ɇɚɫɫɚɫɵ m ɦɚɬɟɪɢɹɥɵԕ ɧԛɤɬɟɝɟ F 1, F 2 , , F n ɤԛɲɬɟɪ ɠԛɣɟɫɿ ԥɫɟɪ ɟɬɫɿɧ.
ɇԛɤɬɟ ԕɨɡԑɚɥɵɫɵɧɵԙ ɧɟɝɿɡɝɿ ɡɚԙɵɧ (3ɚ) ɤɟFɥ&ɟ,ɫɿ ɬԛɪɞɟ ɠɚɡɵɥɚɞɵ:
mɚ&
ɮɨɪɦɭɥɚɞɚԑɵ F – ɛɚɪɥɵԕ ɛɟɥɫɟɧɞɿ ɤԛɲɬɟɪɞɿԙ ɠԥɧɟ ɪɟɚɤɰɢɹɥɚɪɞɵԙ ɬɟԙ ԥɫɟɪ
ɟɬɭɲɿ ɤԛɲɿ.
Ɉɫɵ ɜɟɤɬɨɪɥɵԕ ɬɟԙɞɿɤɬɿԙ ɟɤɿ ɠɚԑɵɧɞɚ ɞɟɤɚɪɚɬɬɵԕ ɤɨɨɪɞɢɧɚɬɬɚɪ
ɠԛɣɟɫɿɧɞɟɝɿ ɨɫɶɬɟɪɝɟ ɩɪɨɟɤɰɢɹɥɚɭԑɚ ɛɨɥɚɞɵ, ɹԑɧɢ:
mɚx Fx , mɚ y Fy , mɚz Fz .
xx xx xx
Ԛɞɟɭɥɟɪɞɿԙ ( wx , wy , wz ) ɩɪɨɟɤɰɢɹɥɚɪɵɧ x , y , z ɚɪԕɵɥɵ ԧɪɧɟɤɬɟɫɟɤ,
mx Fx , my Fy , mz Fz . (7)
Ȼԝɥ ɬɟԙɞɟɭɥɟɪɞɟɝɿ: x, y, z - ɧԛɤɬɟ ԛɞɟɭɿɧɿԙ ɨɫɶɬɟɪɞɟɝɿ ɩɪɨɟɤɰɢɹɥɚɪɵ, Fx ,
Fy , Fz - ɧԛɤɬɟɝɟ ԥɫɟɪ ɟɬɭɲɿ ɤԛɲɬɿԙ ɨɫɵ ɨɫɶɬɟɪɞɟɝɿ ɩɪɨɟɤɰɢɹɥɚɪɵ.
Ⱥɥɵɧԑɚɧ ɬɟԙɞɟɭɥɟɪ (7) ɦɚɬɟɪɢɹɥɵԕ ɧԛɤɬɟ ԕɨɡԑɚɥɵɫɵɧɵԙ ɞɟɤɚɪɬɬɵԕ
ɤɨɨɪɞɢɧɚɬɬɚɪ ɨɫɶɬɟɪɿɧɞɟɝɿ ɞɢɮɮɟɪɟɧɰɢɚɥɞɵԕ ɬɟԙɞɟɭɥɟɪɿ ɞɟɩ ɚɬɚɥɚɞɵ.
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