10 1. , ( ), . , 1 ? 20 . . : Sdx = dV , S − ρSdx = dm, dm dt dm = m0 Sdt m0 Sdt = ρSdx ρR 103 ⋅ 0, 2 = = 1,11⋅104 ≈ 3, 09 t= −3 m0 18 ⋅10 ρdx dt = , m0 2. «! " », " , " 1000 $ " # # 5 . % 10 . & . : ' II $ : F ∆t ( F − F )t1 = − m m m∆v m ( F − F )t1 F = ma1 = = − II t2 mt2 " ∆v = F t2 = Ft1 − F t1 $ # Ft1 103 ⋅ 5 F = = = 330 t2 + t1 5 3. ( ) 300 10 , ? " ; ; 10 : v3 = 2 gR3 − 2 mg3 = γ 4. ' ; mM − R32 " g =γ M − R2 v = v3 2g R = 2 g3 R3 ; " ) ; M R R32 300 M ⋅ R3 = = 30 ≈ 5, 48 R 2 R3 M 10 R3 ⋅ M , 5 10 % . ! 7 º* 0,51 "/ 3. 32 ", $ . : ν1 RT ν RT ; P2 = 2 V V RT P = (ν1 + ν 2 ); (1) V m m ρ1 = 1 ρ2 = 2 (2) V V ρ = ρ1 + ρ2 (3) P1 = 1,2,3 m2, . . . : m2 = 4⋅10-3 " 5. & + .% " , " 3 10 " 3 .& " 3000 , " " .- " . 10 : & , " PV 300 ⋅105 ⋅103 1 1 V2 = = = 300 ⋅103 5 10 P2 PV 1 1 = PV 2 2 : 300000 6. ! . # . U r ! " # . " 16 # , " , " , , " , 25 . , R/2? : I= U ; r U2 U2 Q = I rt ; rt = t1 r r2 U2 Q2 = Q1 = t2 r+R U2 2U 2 U2 Q3 = Q1 = t; t3 = t1 R 3 + 2 r R r r+ 2 2r (t3 − t1 ) 2rt3 = 2rt1 + Rt1 ; R= t1 2 U 2t2 U2 t1 = ; 2t3 − t1 = t2 r t1 r + 2 r (t3 − t1 ) t3 = t2 + t1 25 + 16 = = 20,5 2 2 3