7
(2006-2) . - , , , ( ), v = 70 /.
t. , , v2 t. , , S /v3. , , , , v1:
t + S /v3= (v2 t + S)/v1.
, :
(2007-1) T k , k + 1 (k !). T T : T = (k + 1) T = kT . . T T , T 779 .
(2009-1) 4 300 + 400 = 700 , 500 . , 4 + 4∙(5/7) = 48/7 , 4 + 4∙(7/5) = 48/5 .
A, , m, n. , m ∙(48/7) = n ∙(48/5) , 5∙ m = 7∙ n. m n, ,
, , m = 7 n = 5, A m ∙(48/7) = 7∙(48/7) = 48 = 0,8 .
(2010-1) , . , t = 0,5 v = 5 / . V = 15 / , : .
(2010-2) , 1. 10 10 100 , . 8 180◦ 10 . 3 10 , 360◦. , ,
|
|
,
, ,
1
(. . 2), , 60◦ + 300◦ + 60◦ = 420◦ = (7/3)π, 2 , (7/3)π R + (2/ ) R ≈ 84,8 , 1336,1 , 668,1 ≈ 11 .08 .
. 2
, , -, (. . 3) : α = arcos(3/4) ≈ 41,4◦ , , α ≈ 41,4◦ , 345,6◦ 60,3 . , 1311,6 , 655,8 ≈ 10 .56 .
. 3
(2011-1) 3000/2,5 = 1200 c = 20 , , 10 . 10 , 10 . , 10 .
(2011-2) , h , t . , t: . : . : . h : 5 .
(2011-3) V 1 V 2. , . S, t. .
1. : . . . , ( V 1 V 2) .
2. : , . , . , V 1 V 2.
(2012-1) L . t 1 = 1 = 60 , L / t 1. , t 2 = 40 , L / t 2, L / t 2 L / t 1. 3(L / t 2 L / t 1), 3(L / t 2 L / t 1) L / t 1 = L (3 t 1 4 t 2)/(t 1 t 2). L t 3 = t 1 t 2/(3 t 1 4 t 2) = 120 c.
(2012-2) 0,5 60 / ( 1 /) 0,5 . 0,5 30 / ( 0,5 /) 1 . 0,5 15 / ( 0,25 /.), 0,125 . , 2 1,125 .
|
|
(2012-3) L , V , V , V , , t = 2 . , , t = 3 . , , t , .
, , . :
| V V | = L / t ; | V V | = L / t ; | V V | = L / t .
:
1) V V V V ; || V V | + | V V || = | V V |, L / t + L / t = L / t . t = t × t /(t + t ) = 1,2 .
2) V V V V ; || V V | | V V || = | V V |,
| L / t L / t | = L / t . t = t t /| t t | = 6 . .
(2013-1) 5 . , . , :
,
, , /, ,
() .
:
.
, , D, ,
() 5 21 .
(2006-4) , , , 2 . , , , 23 = 8 . , , r gV, V = a 2 h . , 8 : T = 8r gV.
, , a 0,32 = 32 .
(2007-3) F . F, , P, . , P = 3 F, F = P /3.
, . , h , 3 h, , 3 , , F = P /3.
(2008-3) , . :
() m × l 2 m 2 l + m nl = 0, n = 3;
() 3 m × l 2 m 3 l + m nl = 0, n = 3;
() 2 m 2 l + m 3 l m l 3 m 3 l + m nl = 0, n = 3.
(2008-4) , m = m 0 , . , m 0 g . , mg. , F = (m m 0) g = 6 .
(2008-5) , , mg ( ) Mg ( ), ρ gV /2 ( ) ρ Mg /ρc ( ). , , : (m + M) g = ρ gV /2 + ρ Mg /ρc.
|
|
.
(2009-2) .
, - h, i- mi , , h /2. ,
m 4 gh = (m 0 + mi) gh /2, mi = 2 m 4 m 0 = 1,7 (i = 1, 2, 3).
, T , : m 4 g = T, (m 0 + mi) g = 2 T = 2 m 4 g, .
(2010-3) f 1 f 2 , . , : , . :
,
.
, , , :
,
.
.
, , , . , :
,
, , , :
.
(2013-4) , 5 , .
;
;
.
, , ..,
,
,
.
, :
3 ..
,
(2006-1) , h p = r gh, r , g . , , g . , , . , , , , . , 10 /2 . , g /2. , p = r gR /2 1,61011 = 1,6 !
(2006-3) x . , , , , g [ m + r S (h + x)]. , x: r g x S, . : .
(2007-2) η , , S , . m = ρ Sh η p = mg / S = ρ gh η. . , 10% .
(2007-4) V . , ρ < ρ, ρ gV ρ gV ρ gV. , ρ gV ρ gV = ρ gV. ρ = ρ/2 = 500 /3.
|
|
(2008-2) m , ρ1 ρ2 = ρ1/2 . m /ρ1 2 m /ρ1, 2 m 3 m /ρ1. . : ρ1 = 3ρ/2 = 900 /3, ρ2 = 3ρ/4 = 450 /3.
(2009-3) 12,5 , 20 1 . 250 3, 1000 /. = 1 3/. , 250 h = 0 h = 1 . , 500 . , 750 . 4 , 1000 . h (t) , 250 + 500 + 750 + 1000 = 2500 = 41 40 .
(2009-4) . , , ρ = M/V , : (V + V )ρ = M + m. = (M + m)/ρ V = 32 3,
ρ = M ρ/(M + m ρ V) = 2,5 /3.
V + V = 92 3, , π R 2, Δ h = (V + V )/(π R 2) = (M + m)/(ρπ R 2) ≈ 1,17 .
(2010-4) , , -. - : , : . , , - ,
, ! , ,
, - !
(2011-4) S : .
S , : .
: .
.
.
, , : ,
.
(2012-4) : 17 /10 / = 1,7 . , , 10 × 10 × 2 = 200 3. , 1700 /200 3 = 8,5 /3 = 8500 /3.
(2013-2) , , , , , .
, , .
3;
3;
3;
,
/3.
(2008-1) . , .
V N . , V 0 = V / N , , . V 0= m 0/ρ 1,181029 3.
(2013-3) 35 C .
m , , ; 42 C , .
, l = 5 : .
, .