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2003 .
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2.2. 8
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1, , 2, 3. 4. 4 5, .
1 1 7, . . 8 .
, .
3 :
1. ( ).
2. ( ) .
3. .
. , , . , - , , . . DW=DWk+DWn = 0.
DW=m1v12/2,
m1 - , v1 - .
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, , m1gH. ,
DW= m1 v12/2 - m1gH=0.
v1 :
V1 = (2gH)1/2 (1)
, .. , .
, , , -
( ), , . , , , , , , :
m1v1 = (m1 + m2)v2 (2)
m2 - , v2 - .
(1) (2) , :
v2=m1v1/(mi+m2)=m1(2gH)1/2/(m1+m2) (3)
. , , , - :
DW=DWK +D:=, (4)
. , - , - , :
DWK=WK2 - WK1 = -(m1+m2)v22 /2 (5)
:
DW=W2 W1 = -(mi+m2)gS, (6)
S - .
S f =fS=fScosa, a - . a =p, .
= - fS. (7)
f , f = fcp. (5),(6),(7) (4), :
-(m1+m2)v22/2 - (m1+m2)gS = - fS. (8)
(8) , (3), :
m12gH/(m1+m2) + (m1+m2)gS = fS.
S, :
f = [(m12H/S(m1+m2) + m1+m2]g (9)
, . :
DW = (m1 +m2)v22/2 - m1 v12/2.
(3) v2 (1) v1, :
DW = m12gH/(m1+m2)-migH = m1gH[m1/(m1+m2)-1] = m1m2gH(m1+m2)
, ,
DW/WK2 = m1gHm2/ m1gH(m1 + m2)= m2/(m1+ m2) (10)
: m1 m2. .
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