Page 503 - index

Ɉɧɵԙ ɚɭɞɚɧɵ dA dy ˜ b . Ȼԝɥ ԧɪɧɟɤɬɿ ɢɧɟɪɰɢɹ ɦɨɦɟɧɬɬɟɪiɧɿԙ

ɮɨɪɦɭɥɚɫɵɧɚ ԕɨɹɦɵɡ.
ȿɧɞi ɢɧɬɟɝɪɚɥɞɵ ɟɫɟɩɬɟɣɦiɡ, ɹԑɧɢ:

h
2
y 2dA bh3 . (ɚ)
y 2bdy 12
Ⱥ
³ ³J x1 h
2

Ɉɫɵ ɫɟɤiɥɞi:

J y1 hb3 . (ԥ)
12

ȿɧɞɿ ɯ2 ɠԥɧɟ ɭ2 ɨɫɶɬɟɪiɧɞɟɝi ɢɧɟɪɰɢɹ ɦɨɦɟɧɬɬɟɪɿɧ ɬɚɛɭ ԛɲiɧ (5.11)
ɮɨɪɦɭɥɚɥɚɪɞɵ ԕɨɥɞɚɧɚɦɵɡ.

J x2 J x1 c2 A , J y2 J y1 a 2 A. (ɛ)

ɋɭɪɟɬɬɟɧ ɤԧɪiɧiɩ ɬԝɪԑɚɧɞɚɣ:

c h, a h. (ɜ)
2 2

ɋɨɧɞɚ:

J x2 bh3 , J y2 hb3 . (ɞ)
3 3

2-ɟɫɟɩ. Ɍԝɬɚɫ ɞԧԙɝɟɥɟɤɬiԙ (67-ɫɭɪɟɬ) ɨɫɶɬiɤ ɢɧɟɪɰɢɹ ɦɨɦɟɧɬɬɟɪiɧ (Jx ,Jy)
ɠԥɧɟ ɩɨɥɹɪɥɵԕ ɢɧɟɪɰɢɹ ɦɨɦɟɧɬiɧ ɬɚɛɭ ɤɟɪɟɤ ɛɨɥɫɵɧ.

67-ɫɭɪɟɬ

Ⱥɥɞɵɦɟɧ ɩɨɥɹɪɥɵԕ ɢɧɟɪɰɢɹ ɦɨɦɟɧɬiɧ ɬɚɛɚɦɵɡ. Ɋɚɞɢɭɫɬɚɪɵ U ɠԥɧɟ

U +d U ɤɨɧɰɟɧɬɪɥi ɟɤi ɲɟԙɛɟɪɞiԙ ɤԧɦɟɝiɦɟɧ, ɷɥɟɦɟɧɬɚɪ ɫɚԕɢɧɚ ɛԧɥiɩ ɚɥɚɦɵɡ.
Ɉɧɵԙ ɚɭɞɚɧɵ – dA 2SU ˜ dU .

ɉɨɥɹɪɥɵԕ ɢɧɟɪɰɢɹ ɦɨɦɟɧɬɿɧ ɬɚɛɚɦɵɡ:

U 2 dA KK SR 4 SD 4 .
4 32
U 2 2SU ˜ dU 2S U 3dU

00
³ ³ ³ ³J U

Ɉɫɶɬiɤ ɢɧɟɪɰɢɹ ɦɨɦɟɧɬɬɟɪi ɦɟɧ ɩɨɥɹɪɥɵԕ ɢɧɟɪɰɢɹ ɦɨɦɟɧɬɬɟɪiɧiԙ
ɚɪɚɫɵɧɞɚԑɵ ԕɚɬɵɧɚɫ:

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