. 2011-2012.
.7 .
: 2 .
1. , , . , 4 . ? .
. , , , , , . , 1 , . . 2 , . 4 , , 2 /.
2. . , , . υ3= 100 /. ? ?
. : υ = S/t. , 5/12 , - 1/4 . υ3 = S3 /t3 = 5/3 S/t = 5/3 υ → υ = 3/5 υ 3 → υ = 60 /. : υ1 = S1/t1 ; υ1 = S 2 / 4 t; υ1 = 1/2 υ; υ1 = 30 /. : υ2 = S2/t2; υ2 = S 4 / 3 t; υ2 = 4/3 υ; υ2 = 80 /.
: 60 /; 30 /; 80 /.
3. 5 . , ?
. 3, 3/125. N = 3/ 3/125.
: 125
4. L .
. 20 .
. , , .
. .
.
L, d, h, V , , . S (. 1). Ÿ , S = πR 2 − πR 2, , . d .
2011-2012.
. 8 .
: 2 .
|
|
1. . , , . υ3= 100 /. ? ?
. : υ = S/t. , 5/12 , - 1/4 . υ3 = S3 /t3 = 5/3 S/t = 5/3 υ → υ = 3/5 υ 3 → υ = 60 /. : υ1 = S1/t1 ; υ1 = S 2 / 4 t; υ1 = 1/2 υ; υ1 = 30 /. : υ2 = S2/t2; υ2 = S 4 / 3 t; υ2 = 4/3 υ; υ2 = 80 /.
2. , ρ = 600 /3. , , 2 . .
. ρ = m /V
V= V1 + V2,
V1 = m1 /V1
V2 = m2 /V2
ρ = m / V1 + V2 = 4/3 ρ 2
ρ 2 = 450 /3 ρ 1 = 900 /3
: 450 900 /3.
3. , , , . 50 . ?
L l
Mg
mg
. L ,
MgL/2 = mg (L - L)/2
ρ1L2 = ρ2 (L - L)2
L =0,77
: 0,77
4. L .
. 20 .
. , , .
. .
L, d, h, V , , . S (. 1). Ÿ , S = πR 2 − πR 2, , . d .