(, ) . , . . , . . , . .
6. m l a. B. I (. 10). .
.
,
( ). α ,
tgα = FA/mg = IBl/mg.
. 10.
, , g*, g* α g
.
.
7. m, d R (R>>d), k . (. 11). .
.
, (. 12). , .
. 11.
, , , . (≈ 10-14).
, σ v ( ). .
F = evB.
,
F = eE = e σ/ε0.
σ = ε0vB.
. 12. , .
, σ. .
|
|
,
S = πR2 ; .
, F, .
.
,
.
, ,
.
: , ; .
.
. ? , E = vB,
,
, :
. , .
8.
. m, , - 0. , (. 12), . .
. , (. 12).
, .
F. = mgsin α - Fmcos α, Fm , .
Fm = Tsinα0 ,
mg = Tcosα0, , , Fm = mg tgα0,
. 12.
.
.
)
; ;
; ; .
.
,
. .
:
; ; ;
; ;
; , . . : ;
; ; .
: .
9.
, . η = 5,0 . ? .
.
, (, ) . ( ). ( ), , . .
, :
|
|
Jc φ" = - M;
Jc , . . 2, 46, . 136, , m
= m sin φ.
φ" + φ = 0,
ω02 = .
:
0 = 2π ; 01 = 2π .
01 = . η , η2 .
, , .
10. L , a. - m ( ). , (. 14). (t). .
.
v ABCD . , . i AD. ...
Ɛ = - = - (BS) = - (Bax),
. 14.
B a , = v .
, :
ƐL = - L = - Ba .
i = (Ba/L) (x0 -x),
x0 .
,
FA = iaB = (x0 -x).
mx" = mg + FA.
x" = g + (x0 -x).
ω02 = .
x" + ω02 = g + ω02 x0
.
x(t) = (x0 + ) + A cos ω0t (55)
. , v(0) = 0. 0. (t) :
= - . t = 0 , x0 = 0.
x(t) = - cos ω0t.